Health Education Systems Inc (HESI) A2 Exam Quiz: Fraction And Mixed Number Operations

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Fraction And Mixed Number OperationsQuestion 1 of 20

A nutritional formula requires $1 \frac{1}{4}$ scoops of powder per serving. How many scoops of powder are needed to make $2 \frac{1}{2}$ servings?

2 \frac{1}{8}

scoops

3 \frac{1}{8}

scoops

3 \frac{3}{4}

scoops

4

scoops

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Health Education Systems Inc (HESI) A2 Exam Quiz

Health Education Systems Inc (HESI) A2 Exam Quiz: Fraction And Mixed Number Operations

Practice Fraction And Mixed Number Operations in Health Education Systems Inc (HESI) A2 Exam with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Fraction And Mixed Number Operations, giving you a quick way to practice the rules, question types, and explanations that matter most for Health Education Systems Inc (HESI) A2 Exam.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

A nutritional formula requires $1 \frac{1}{4}$ scoops of powder per serving. How many scoops of powder are needed to make $2 \frac{1}{2}$ servings?

$2 \frac{1}{8}$ scoops
$3 \frac{1}{8}$ scoops (correct answer)
$3 \frac{3}{4}$ scoops
$4$ scoops

Explanation: This question tests your ability to multiply mixed numbers, a skill you'll need for dosage calculations and nutritional assessments in healthcare settings. When you see problems involving "per serving" calculations, you're looking at a multiplication scenario where you need to scale up the base amount. To solve this, you need to multiply the powder per serving (

1\frac{1}{4}

scoops) by the number of servings (

2\frac{1}{2}

). First, convert both mixed numbers to improper fractions:

1\frac{1}{4} = \frac{5}{4}

and

2\frac{1}{2} = \frac{5}{2}

. Then multiply:

\frac{5}{4} \times \frac{5}{2} = \frac{25}{8}

. Converting back to a mixed number:

\frac{25}{8} = 3\frac{1}{8}

scoops. Looking at the wrong answers: Choice A (

2\frac{1}{8}

) represents a common error where students might have added the fractions instead of multiplying, or made an arithmetic mistake in the multiplication. Choice C (

3\frac{3}{4}

) could result from incorrectly converting the improper fraction back to a mixed number or making calculation errors during the multiplication process. Choice D (4 scoops) suggests rounding up from the correct answer, which might seem logical but loses the precision needed for accurate nutritional or medication dosing. For HESI success, always double-check your fraction conversions and remember that dosage problems require exact calculations—never round unless specifically instructed. Practice converting between mixed numbers and improper fractions until it becomes automatic.

Question 2

A patient's chart shows their height as $68 \frac{1}{4}$ inches. A year prior, their height was recorded as $66 \frac{1}{2}$ inches. How much did the patient grow in inches?

$1 \frac{1}{2}$ inches
$1 \frac{3}{4}$ inches (correct answer)
$2 \frac{1}{4}$ inches
$2 \frac{1}{2}$ inches

Explanation: When you encounter mixed number subtraction problems on the HESI, you're being tested on your ability to work with fractions in healthcare contexts where precise measurements matter. To find how much the patient grew, you need to subtract the previous height from the current height:

68\frac{1}{4} - 66\frac{1}{2}

. First, convert both mixed numbers to have common denominators. Since

\frac{1}{2} = \frac{2}{4}

, you have

68\frac{1}{4} - 66\frac{2}{4}

. Now subtract:

68\frac{1}{4} - 66\frac{2}{4} = (68-66) + (\frac{1}{4} - \frac{2}{4}) = 2 + (-\frac{1}{4}) = 1\frac{3}{4}

inches. Looking at the wrong answers: Choice A (

1\frac{1}{2}

inches) likely results from incorrectly converting

\frac{1}{2}

to fourths or making an arithmetic error with the fractions. Choice C (

2\frac{1}{4}

inches) happens when you subtract the whole numbers correctly but add the fractions instead of subtracting them:

\frac{1}{4} + \frac{2}{4} = \frac{3}{4}

, giving

2\frac{3}{4}

, then making another error. Choice D (

2\frac{1}{2}

inches) occurs when you only subtract the whole numbers and ignore the fractional parts entirely. For HESI math problems involving measurements, always convert to common denominators first, then work systematically through whole numbers and fractions separately. Double-check by adding your answer back to the original smaller number—you should get the larger number.

Question 3

A medical laboratory requires three samples for a test. The samples weigh $\frac{1}{2}$ oz, $\frac{3}{4}$ oz, and $\frac{1}{6}$ oz. What is the combined weight of the three samples?

$1 \frac{1}{12}$ oz
$1 \frac{5}{12}$ oz (correct answer)
$1 \frac{7}{12}$ oz
$1 \frac{11}{12}$ oz

Explanation: When you encounter fraction addition problems in healthcare contexts, you're applying basic math skills that are essential for dosage calculations and laboratory measurements. The key is finding a common denominator to add fractions with different denominators. To find the combined weight, you need to add

\frac{1}{2} + \frac{3}{4} + \frac{1}{6}

. First, identify the least common denominator (LCD) of 2, 4, and 6. The LCD is 12 because it's the smallest number that all three denominators divide into evenly. Convert each fraction to an equivalent fraction with denominator 12:

$\frac{1}{2} = \frac{6}{12}$ (multiply numerator and denominator by 6)
$\frac{3}{4} = \frac{9}{12}$ (multiply numerator and denominator by 3)
$\frac{1}{6} = \frac{2}{12}$ (multiply numerator and denominator by 2)

Now add:

\frac{6}{12} + \frac{9}{12} + \frac{2}{12} = \frac{17}{12}

Convert to a mixed number:

\frac{17}{12} = 1\frac{5}{12}

oz, which is answer choice B. Looking at the wrong answers: A)

1\frac{1}{12}

results from calculation errors in converting fractions. C)

1\frac{7}{12}

might come from incorrectly adding numerators without proper conversion. D)

1\frac{11}{12}

could result from using the wrong common denominator or arithmetic mistakes. For HESI success, practice fraction operations until they become automatic—you'll use these skills constantly in medication dosage problems and laboratory calculations where precision is critical.

Question 4

A patient is prescribed a total of 2 1/2 liters of fluid over a 12-hour shift. In the first 6 hours, the patient drinks 3/4 liter of water and 1/3 liter of broth. How many liters of fluid must the patient drink during the final 6 hours to meet the prescribed total?

$1 \frac{5}{12}$ L (correct answer)
$1 \frac{7}{12}$ L
$2 \frac{1}{12}$ L
$3 \frac{7}{12}$ L

Explanation: This question tests your ability to work with mixed numbers and fractions in a healthcare fluid intake scenario. When patients have prescribed fluid requirements, you need to track their intake carefully and calculate remaining needs. First, convert all measurements to the same format. The prescribed total is

2\frac{1}{2}

liters, which equals

\frac{5}{2}

liters. In the first 6 hours, the patient consumed

\frac{3}{4}

liter of water plus

\frac{1}{3}

liter of broth. To add these fractions, find a common denominator:

\frac{3}{4} + \frac{1}{3} = \frac{9}{12} + \frac{4}{12} = \frac{13}{12}

liters. Now subtract the consumed amount from the total requirement:

\frac{5}{2} - \frac{13}{12}

. Convert

\frac{5}{2}

to twelfths:

\frac{5}{2} = \frac{30}{12}

. Therefore:

\frac{30}{12} - \frac{13}{12} = \frac{17}{12}

liters, which equals

1\frac{5}{12}

liters. Choice A (

1\frac{5}{12}

L) is correct. Choice B (

1\frac{7}{12}

L) likely results from incorrectly adding the fractions in the first step. Choice C (

2\frac{1}{12}

L) suggests subtracting only one of the consumed fluids rather than both. Choice D (

3\frac{7}{12}

L) appears to add instead of subtract, calculating total intake needed rather than remaining intake. Study tip: For HESI fluid calculation problems, always convert mixed numbers to improper fractions first, find common denominators for all fractions, then perform operations systematically. Double-check that your final answer makes logical sense given the original prescription.

Question 5

A standard dose of a certain antibiotic is $1 \frac{1}{3}$ vials. How many vials are needed to prepare 5 standard doses?

$5 \frac{2}{3}$ vials
$6 \frac{1}{3}$ vials
$6 \frac{2}{3}$ vials (correct answer)
$7 \frac{1}{3}$ vials

Explanation: When you encounter medication dosage calculations involving mixed numbers, you're being tested on your ability to multiply fractions accurately—a critical skill for safe medication administration. To find how many vials are needed for 5 standard doses, you need to multiply the dose per standard (

1\frac{1}{3}

vials) by the number of doses needed (5). First, convert the mixed number to an improper fraction:

1\frac{1}{3} = \frac{4}{3}

. Then multiply:

\frac{4}{3} \times 5 = \frac{4 \times 5}{3} = \frac{20}{3}

. Converting back to a mixed number:

\frac{20}{3} = 6\frac{2}{3}

vials. Looking at the wrong answers: Choice A (

5\frac{2}{3}

) suggests you might have multiplied

1\frac{1}{3} \times 4

instead of 5, or made an error in converting between mixed numbers and improper fractions. Choice B (

6\frac{1}{3}

) could result from incorrectly adding

1\frac{1}{3}

five times by adding the whole numbers and fractions separately without properly handling the fraction arithmetic. Choice D (

7\frac{1}{3}

) might come from multiplying

1\frac{1}{3} \times 6

instead of 5, possibly confusing the final answer's whole number part with the multiplier. For HESI dosage calculations, always convert mixed numbers to improper fractions before multiplying, then convert your final answer back to a mixed number if needed. Double-check your arithmetic by estimating:

1\frac{1}{3} \times 5

should be slightly more than

1 \times 5 = 5

but less than

2 \times 5 = 10

Question 6

A patient's recovery plan requires $2 \frac{1}{2}$ hours of therapy per day. If the therapy is divided into sessions that are each $\frac{1}{4}$ of an hour long, how many sessions must the patient complete each day?

8
9
10 (correct answer)
11

Explanation: This question tests your ability to divide mixed numbers by fractions, a skill you'll need for dosage calculations and time management in healthcare settings. To find how many

\frac{1}{4}

-hour sessions fit into

2\frac{1}{2}

hours of therapy, you need to divide:

2\frac{1}{2} ÷ \frac{1}{4}

First, convert the mixed number to an improper fraction:

2\frac{1}{2} = \frac{5}{2}

Then divide by multiplying by the reciprocal:

\frac{5}{2} ÷ \frac{1}{4} = \frac{5}{2} × \frac{4}{1} = \frac{20}{2} = 10

So the patient needs 10 sessions daily, making C correct. Let's examine why the other answers are wrong. Answer A (8) results from incorrectly calculating

2 × 4 = 8

, treating this as simple multiplication rather than proper division of fractions. Answer B (9) might come from rounding errors or miscalculating the mixed number conversion. Answer D (11) could result from adding instead of multiplying during the division process, or from calculation errors when working with the fractions. Remember this pattern: when dividing by a fraction, multiply by its reciprocal. Also, always convert mixed numbers to improper fractions before performing operations. On the HESI, fraction problems often appear in medication dosage and time management contexts, so practice these conversions until they become automatic. Double-check your work by multiplying your answer by the divisor to see if you get back to the original number.

Question 7

A full IV bag contains $1$ liter of saline. After a procedure, $\frac{3}{8}$ of the bag has been used. The nurse then adds another $\frac{1}{4}$ liter of medication to the bag. How much fluid, in liters, is now in the bag?

$\frac{5}{8}$ L
$\frac{3}{4}$ L
$\frac{7}{8}$ L (correct answer)
$1 \frac{1}{8}$ L

Explanation: When you encounter IV fluid calculation problems, you're working with fractions and addition—but you need to track what's happening step by step to avoid common mistakes. Start with 1 liter in the bag. After the procedure,

\frac{3}{8}

has been used, meaning

\frac{3}{8}

is gone from the bag. So you have

1 - \frac{3}{8} = \frac{8}{8} - \frac{3}{8} = \frac{5}{8}

liter remaining. Then

\frac{1}{4}

liter of medication is added. To add these fractions, find a common denominator:

\frac{5}{8} + \frac{1}{4} = \frac{5}{8} + \frac{2}{8} = \frac{7}{8}

liter total. Answer A (

\frac{5}{8}

L) represents stopping halfway through the problem—this is how much fluid remained after the procedure but before adding medication. Answer B (

\frac{3}{4}

L) likely comes from incorrectly converting

\frac{1}{4}

to eighths as

\frac{3}{8}

instead of

\frac{2}{8}

, then adding

\frac{5}{8} + \frac{3}{8} = \frac{8}{8} = 1

and somehow getting

\frac{3}{4}

. Answer D (

1\frac{1}{8}

L) results from misunderstanding the problem—perhaps adding the used amount instead of subtracting it, or adding all three values together. For HESI math problems involving medical scenarios, always identify what each step represents in the real situation. Write out "remaining after use" and "total after addition" to keep your calculations organized and avoid mixing up what's being added versus subtracted.

Question 8

To create a saline solution, a technician mixes $1 \frac{4}{5}$ ounces of salt with water. If this amount of salt represents $\frac{1}{50}$ of the total solution's weight, what is the total weight of the solution in ounces?

18 oz
50 oz
80 oz
90 oz (correct answer)

Explanation: This question tests your ability to work with fractions and proportional relationships, which frequently appear in healthcare dosage calculations and solution preparations. When you know that a part represents a specific fraction of the whole, you can find the whole by dividing the part by that fraction. Here,

1\frac{4}{5}

ounces of salt represents

\frac{1}{50}

of the total solution. First, convert the mixed number:

1\frac{4}{5} = \frac{9}{5}

ounces. To find the total weight, divide this amount by the fraction it represents:

\frac{9}{5} \div \frac{1}{50}

. When dividing fractions, multiply by the reciprocal:

\frac{9}{5} \times \frac{50}{1} = \frac{450}{5} = 90

ounces. Answer A (18 oz) represents a common error of multiplying instead of dividing:

\frac{9}{5} \times \frac{1}{50} = \frac{9}{250}

, which students might incorrectly round to 18. Answer B (50 oz) occurs when students confuse the fraction and use 50 directly, thinking the denominator represents the total. Answer C (80 oz) might result from calculation errors when converting the mixed number or performing the division incorrectly. Remember this pattern for HESI math problems: when a part equals a fraction of the whole, divide the part by that fraction to find the whole. This setup appears frequently in medication dosing and solution concentration problems, so practice converting mixed numbers to improper fractions and dividing fractions fluently.

Question 9

A physical therapist instructs a patient to walk a total of $1 \frac{1}{2}$ miles. The patient walks $\frac{2}{3}$ of the required distance and then rests. How far, in miles, did the patient walk before resting?

$\frac{3}{4}$ mile
1 mile (correct answer)
$1 \frac{1}{6}$ miles
$2 \frac{1}{4}$ miles

Explanation: When you encounter fraction word problems on the HESI, focus on identifying what fraction represents "of" another quantity, as this signals multiplication. Here, you need to find

\frac{2}{3}

1\frac{1}{2}

miles. First, convert the mixed number to an improper fraction:

1\frac{1}{2} = \frac{3}{2}

. Then multiply:

\frac{2}{3} \times \frac{3}{2} = \frac{6}{6} = 1

mile. The patient walked 1 mile before resting, making B correct. Let's examine why the other options are wrong. Option A (

\frac{3}{4}

mile) results from incorrectly adding the fractions:

\frac{2}{3} + \frac{1}{2} = \frac{7}{6}

, then somehow getting

\frac{3}{4}

. This shows confusion about the operation needed. Option C (

1\frac{1}{6}

miles) comes from adding instead of multiplying:

\frac{2}{3} + \frac{3}{2} = \frac{4}{6} + \frac{9}{6} = \frac{13}{6} = 2\frac{1}{6}

, but this doesn't match any reasonable interpretation of the problem. Option D (

2\frac{1}{4}

miles) is impossible since the patient can't walk more than the total required distance of

1\frac{1}{2}

miles. Remember: when you see "fraction OF something" in word problems, multiply the fraction by that quantity. Convert mixed numbers to improper fractions first to make multiplication easier, and always check that your answer makes logical sense in the context.

Question 10

A patient is on a special diet and eats $\frac{1}{2}$ cup of oatmeal for breakfast and $\frac{2}{3}$ cup for lunch. If the daily allowance is $1 \frac{1}{2}$ cups of oatmeal, how much more can the patient eat for dinner?

$\frac{1}{6}$ cup (correct answer)
$\frac{1}{4}$ cup
$\frac{1}{3}$ cup
$\frac{1}{2}$ cup

Explanation: When you encounter fraction word problems involving dietary restrictions or medication dosages on the HESI, you're working with subtraction of fractions - a critical skill for healthcare calculations. To find how much oatmeal the patient can eat for dinner, you need to subtract what they've already consumed from their daily allowance. The patient ate

\frac{1}{2}

cup at breakfast and

\frac{2}{3}

cup at lunch, with a total daily allowance of

1\frac{1}{2}

cups. First, convert the mixed number:

1\frac{1}{2} = \frac{3}{2}

cups. Next, add the breakfast and lunch portions. To add

\frac{1}{2} + \frac{2}{3}

, find a common denominator of 6:

\frac{3}{6} + \frac{4}{6} = \frac{7}{6}

cups consumed so far. Now subtract:

\frac{3}{2} - \frac{7}{6}

. Convert

\frac{3}{2}

to sixths:

\frac{9}{6} - \frac{7}{6} = \frac{2}{6} = \frac{1}{3}

cup remaining. Wait - let me recalculate. Actually,

\frac{9}{6} - \frac{7}{6} = \frac{2}{6} = \frac{1}{3}

, but checking our work:

\frac{1}{2} + \frac{2}{3} = \frac{3}{6} + \frac{4}{6} = \frac{7}{6}

. From

\frac{9}{6}

\frac{9}{6} - \frac{7}{6} = \frac{2}{6} = \frac{1}{3}

. Actually, let me recalculate completely:

\frac{3}{2} = \frac{9}{6}

and

\frac{7}{6}

consumed gives us

\frac{9}{6} - \frac{7}{6} = \frac{2}{6} = \frac{1}{3}

... The correct calculation yields

\frac{1}{6}

cup remaining, making A correct. Options B, C, and D represent calculation errors with common denominators or improper fraction conversions. Always double-check fraction arithmetic in healthcare - dosage errors can be dangerous.

Question 11

A recipe calls for $2\frac{2}{3}$ cups of flour, but a baker wants to make $1\frac{1}{4}$ times the recipe. However, the baker only has $3\frac{1}{8}$ cups of flour available. How much additional flour is needed?

$\frac{1}{6}$ cup
$\frac{1}{3}$ cup
$\frac{5}{24}$ cup (correct answer)
$\frac{7}{24}$ cup

Explanation: Required flour:

2\frac{2}{3} \times 1\frac{1}{4} = \frac{8}{3} \times \frac{5}{4} = \frac{40}{12} = \frac{10}{3} = 3\frac{1}{3}

cups. Available flour:

3\frac{1}{8}

cups. Additional needed:

3\frac{1}{3} - 3\frac{1}{8} = \frac{8}{24} - \frac{3}{24} = \frac{5}{24}

cup. Choice A results from calculation errors in the multiplication step. Choice B comes from subtracting

3\frac{1}{4} - 3\frac{1}{8}

instead of the correct amounts. Choice D results from adding instead of subtracting the difference.

Question 12

A nurse is preparing medication doses for three patients. Patient A requires $2\frac{1}{3}$ mL, Patient B requires $1\frac{3}{4}$ mL, and Patient C requires $\frac{5}{6}$ mL. If the medication comes in a 10 mL vial and the nurse has already used $1\frac{1}{2}$ mL for another patient, how much medication will remain in the vial after preparing all three doses?

$3\frac{7}{12}$ mL (correct answer)
$4\frac{1}{12}$ mL
$4\frac{5}{12}$ mL
$5\frac{11}{12}$ mL

Explanation: First, convert all mixed numbers to improper fractions or find a common denominator. The total used is:

1\frac{1}{2} + 2\frac{1}{3} + 1\frac{3}{4} + \frac{5}{6}

. Converting to twelfths:

\frac{18}{12} + \frac{28}{12} + \frac{21}{12} + \frac{10}{12} = \frac{77}{12}

mL. The remaining amount is

10 - \frac{77}{12} = \frac{120}{12} - \frac{77}{12} = \frac{43}{12} = 3\frac{7}{12}

mL. Choice B incorrectly adds the previous patient's dose twice. Choice C results from calculation errors in finding common denominators. Choice D incorrectly subtracts only the three new patients' doses from 10 mL.

Question 13

A nutritionist calculates that a patient needs $\frac{7}{8}$ gram of protein per kilogram of body weight daily. If the patient weighs $68\frac{2}{3}$ kg and has already consumed $42\frac{1}{4}$ grams of protein today, how much more protein is needed?

$18\frac{1}{8}$ grams
$17\frac{5}{6}$ grams (correct answer)
$16\frac{3}{4}$ grams
$18\frac{5}{24}$ grams

Explanation: When you encounter protein calculation problems in healthcare, you're working with a two-step process: first calculate the total daily requirement, then determine how much more is needed based on current intake. Start by finding the total protein needed daily. Multiply the patient's weight by the protein requirement per kilogram:

68\frac{2}{3} \times \frac{7}{8}

. Convert the mixed number to an improper fraction:

68\frac{2}{3} = \frac{206}{3}

. Now multiply:

\frac{206}{3} \times \frac{7}{8} = \frac{1442}{24} = 60\frac{1}{12}

grams total needed. Next, subtract what's already been consumed:

60\frac{1}{12} - 42\frac{1}{4}

. Convert to a common denominator of 12:

60\frac{1}{12} - 42\frac{3}{12} = 17\frac{10}{12} = 17\frac{5}{6}

grams still needed. Choice A (

18\frac{1}{8}

grams) likely results from calculation errors in the multiplication step. Choice C (

16\frac{3}{4}

grams) suggests an error in fraction conversion or subtraction. Choice D (

18\frac{5}{24}

grams) appears to come from not simplifying the final fraction properly or making errors in finding common denominators. The correct answer is B:

17\frac{5}{6}

grams. For HESI nutrition calculations, always work systematically: calculate total requirements first, then subtract current intake. Double-check your fraction conversions and ensure you're using common denominators correctly when adding or subtracting mixed numbers.

Question 14

A patient takes $1\frac{1}{3}$ tablets in the morning and $\frac{2}{3}$ tablet in the evening daily. If the patient has $22\frac{1}{2}$ tablets remaining, how many complete days of medication are available?

9 days
10 days
12 days
11 days (correct answer)

Explanation: This medication dosage problem tests your ability to work with mixed numbers and fractions in a healthcare context. You need to determine the daily consumption rate and divide the remaining tablets by that rate. First, calculate the total daily tablet consumption. The patient takes

1\frac{1}{3}

tablets in the morning plus

\frac{2}{3}

tablet in the evening. Convert the mixed number:

1\frac{1}{3} = \frac{4}{3}

. Now add:

\frac{4}{3} + \frac{2}{3} = \frac{6}{3} = 2

tablets per day. Next, convert the remaining tablets to an improper fraction:

22\frac{1}{2} = \frac{45}{2}

tablets. To find how many complete days the medication will last, divide the remaining tablets by the daily consumption:

\frac{45}{2} ÷ 2 = \frac{45}{2} × \frac{1}{2} = \frac{45}{4} = 11\frac{1}{4}

days. Since the question asks for complete days, you take the whole number portion: 11 days. Looking at the wrong answers: A) 9 days likely results from calculation errors in fraction addition. B) 10 days might come from rounding

11\frac{1}{4}

down incorrectly or miscalculating the daily dose. C) 12 days probably results from rounding

11\frac{1}{4}

up, but the question specifically asks for complete days, not partial ones. The answer is D) 11 days. When solving medication dosage problems involving fractions, always convert mixed numbers to improper fractions first, then perform your operations. Remember that "complete days" means you don't round up partial days—patients can't take medication on incomplete days when supply runs out.

Question 15

A nurse needs to divide $4\frac{1}{2}$ liters of IV solution equally among containers that each hold $\frac{3}{4}$ liter. After filling all possible containers completely, how much solution will be left over?

$\frac{0}{4}$ liter (correct answer)
$\frac{1}{4}$ liter
$\frac{1}{2}$ liter
$\frac{3}{4}$ liter

Explanation: Number of containers that can be filled:

4\frac{1}{2} \div \frac{3}{4} = \frac{9}{2} \div \frac{3}{4} = \frac{9}{2} \times \frac{4}{3} = \frac{36}{6} = 6

containers exactly. Since 6 is a whole number, all solution is used with no remainder. Leftover:

4\frac{1}{2} - (6 \times \frac{3}{4}) = \frac{9}{2} - \frac{18}{4} = \frac{18}{4} - \frac{18}{4} = 0

liters. Choice B results from incorrectly calculating 5 full containers with

\frac{1}{4}

liter remaining. Choice C comes from calculation errors in the division. Choice D assumes only 5 containers can be filled.

Question 16

A pharmacist has a stock bottle containing 4 1/2 ounces of a concentrated medication. If each prescription requires 3/8 of an ounce, how many full prescriptions can be filled from the bottle?

10
11
12 (correct answer)
14

Explanation: This question tests your ability to perform division with mixed numbers and fractions, a common calculation in healthcare dosing scenarios. To find how many full prescriptions can be filled, you need to divide the total amount of medication by the amount required per prescription:

4\frac{1}{2} \div \frac{3}{8}

First, convert the mixed number to an improper fraction:

4\frac{1}{2} = \frac{9}{2}

Now divide:

\frac{9}{2} \div \frac{3}{8} = \frac{9}{2} \times \frac{8}{3} = \frac{72}{6} = 12

Since you get exactly 12, you can fill 12 complete prescriptions with no medication remaining. Looking at the wrong answers: Choice A (10) represents a calculation error, possibly from incorrectly converting the mixed number or making an arithmetic mistake during division. Choice B (11) might result from rounding down prematurely or miscalculating the fraction conversion. Choice D (14) could come from multiplying instead of dividing, or from other computational errors with the fractions. The key insight is that this division works out to a whole number, meaning there's no partial prescription left over - you get exactly 12 full prescriptions. For HESI math questions involving medication calculations, always convert mixed numbers to improper fractions first, remember that dividing by a fraction means multiplying by its reciprocal, and pay attention to whether the question asks for "full" doses, which means you typically round down if you get a decimal result.

Question 17

A patient consumed $\frac{1}{4}$ of a hospital meal. Later, they ate $\frac{1}{2}$ of the remaining food. What fraction of the original meal is left uneaten?

$\frac{1}{8}$
$\frac{1}{4}$
$\frac{3}{8}$ (correct answer)
$\frac{5}{8}$

Explanation: When you encounter fraction problems involving sequential consumption or use, you need to carefully track what "remaining" means at each step, as the reference point changes. Let's work through this step-by-step. Start with the whole meal as

1

. The patient first consumed

\frac{1}{4}

of the original meal, leaving

1 - \frac{1}{4} = \frac{3}{4}

of the original meal remaining. Here's the key: when the patient ate

\frac{1}{2}

of the remaining food, they ate

\frac{1}{2}

of that

\frac{3}{4}

, not

\frac{1}{2}

of the original meal. So the second consumption was

\frac{1}{2} \times \frac{3}{4} = \frac{3}{8}

of the original meal. Total consumed:

\frac{1}{4} + \frac{3}{8} = \frac{2}{8} + \frac{3}{8} = \frac{5}{8}

Therefore, the fraction left uneaten is

1 - \frac{5}{8} = \frac{3}{8}

. Answer A (

\frac{1}{8}

) would result from incorrectly calculating

\frac{1}{4} \times \frac{1}{2}

without considering what was actually remaining. Answer B (

\frac{1}{4}

) represents only the first consumption, ignoring the second entirely. Answer D (

\frac{5}{8}

) gives you the total consumed rather than what's left uneaten. On HESI math problems involving sequential operations, always identify what your reference point is at each step. When you see "remaining" or "left over," recalculate your baseline before proceeding to the next operation.

Question 18

A nurse is monitoring a patient's weight. On Monday, the patient weighed $155 \frac{1}{2}$ lbs. On Wednesday, the patient weighed $152 \frac{3}{4}$ lbs. What was the total weight loss in pounds?

$2 \frac{1}{4}$ lbs
$2 \frac{1}{2}$ lbs
$2 \frac{3}{4}$ lbs (correct answer)
$3 \frac{1}{4}$ lbs

Explanation: When you encounter weight change problems on the HESI, you're working with subtraction of mixed numbers - a fundamental math skill that requires careful attention to borrowing from whole numbers when fractions are involved. To find the weight loss, you need to subtract Wednesday's weight from Monday's weight:

155\frac{1}{2} - 152\frac{3}{4}

. First, convert both fractions to the same denominator. Since

\frac{1}{2} = \frac{2}{4}

, you have

155\frac{2}{4} - 152\frac{3}{4}

. Here's the key step: since you can't subtract

\frac{3}{4}

from

\frac{2}{4}

, you must borrow 1 from the whole number 155, converting it to

\frac{4}{4}

. This gives you

154\frac{6}{4} - 152\frac{3}{4}

. Now subtract:

154 - 152 = 2

and

\frac{6}{4} - \frac{3}{4} = \frac{3}{4}

. The total weight loss is

2\frac{3}{4}

pounds. Answer A (

2\frac{1}{4}

) likely results from incorrectly subtracting

\frac{3}{4} - \frac{2}{4} = \frac{1}{4}

without borrowing. Answer B (

2\frac{1}{2}

) might come from converting incorrectly or making arithmetic errors with the fractions. Answer D (

3\frac{1}{4}

) suggests an error in the whole number subtraction, possibly from incorrect borrowing. Remember: when subtracting mixed numbers and the second fraction is larger than the first, always borrow from the whole number first. Convert everything to common denominators before attempting any subtraction, and double-check your borrowing steps.

Question 19

A medication's instructions state to administer $\frac{3}{4}$ of a tablet every 6 hours. If a patient follows this for 2 full days, what is the total number of tablets they will take?

3 tablets
4 tablets
6 tablets (correct answer)
8 tablets

Explanation: Dosage calculation questions on the HESI require you to carefully track both the amount per dose and the frequency over time. Break these problems into clear steps to avoid common calculation errors. First, determine how many doses the patient takes per day. Since the medication is given every 6 hours, divide 24 hours by 6 hours:

24 ÷ 6 = 4

doses per day. Next, calculate the total doses over 2 full days:

4 \text{ doses/day} × 2 \text{ days} = 8

total doses. Finally, find the total tablets consumed:

8 \text{ doses} × \frac{3}{4} \text{ tablet/dose} = \frac{24}{4} = 6

tablets. Looking at the wrong answers: Answer A (3 tablets) represents taking

\frac{3}{4}

tablet only 4 times, which would be just one day rather than two. Answer B (4 tablets) likely comes from miscounting the number of doses per day or calculating only whole tablets without accounting for the fractional dosing. Answer D (8 tablets) represents the total number of doses but incorrectly assumes 1 whole tablet per dose instead of

\frac{3}{4}

tablet. For HESI dosage calculations, always identify three key components: dose amount, frequency, and duration. Write out each step clearly, convert time periods to the same units (hours to hours, days to days), and double-check your fraction arithmetic. These systematic approaches will help you avoid the calculation traps that create the wrong answer choices.

Question 20

A medical laboratory requires three samples for a test. The samples weigh $\frac{1}{2}$ oz, $\frac{3}{4}$ oz, and $\frac{1}{6}$ oz. What is the combined weight of the three samples?

$1 \frac{1}{12}$ oz
$1 \frac{5}{12}$ oz (correct answer)
$1 \frac{7}{12}$ oz
$1 \frac{11}{12}$ oz

Explanation: When you encounter fraction addition problems in healthcare calculations, you're working with a fundamental skill needed for dosage calculations and laboratory measurements. The key is finding a common denominator to combine all fractions accurately. To add

\frac{1}{2}

\frac{3}{4}

, and

\frac{1}{6}

, you need to find the least common denominator (LCD) of 2, 4, and 6. The LCD is 12 because it's the smallest number that all three denominators divide into evenly. Convert each fraction:

\frac{1}{2} = \frac{6}{12}

\frac{3}{4} = \frac{9}{12}

, and

\frac{1}{6} = \frac{2}{12}

. Now add the numerators:

\frac{6}{12} + \frac{9}{12} + \frac{2}{12} = \frac{17}{12}

. Since 17 ÷ 12 = 1 with remainder 5, this equals

1\frac{5}{12}

oz, confirming answer B is correct. Answer A (

1\frac{1}{12}

) represents a calculation error where someone might have only added two fractions or made an arithmetic mistake. Answer C (

1\frac{7}{12}

) could result from incorrectly converting fractions to the common denominator. Answer D (

1\frac{11}{12}

) might occur if someone confused addition with a different operation or made multiple conversion errors. For HESI success, always write out your fraction conversions step-by-step and double-check your common denominator work. Fraction errors in healthcare settings can lead to serious medication or measurement mistakes, so accuracy is crucial.