ISEE Middle Level Math : Numbers and Operations

Study concepts, example questions & explanations for ISEE Middle Level Math

varsity tutors app store varsity tutors android store

Example Questions

Example Question #1 : How To Find The Whole From The Part With Percentage

If sales tax on a pair of jeans is , and the jeans cost  before tax, what is the final price of the jeans including tax?

Possible Answers:

$60

$66

$56

$62

$58

Correct answer:

$58

Explanation:

Since the jeans are the only item being purchased, and they cost $, we must first find % of $.  In order to do that we multiply $ by the decimal form of %, which is .

Note: In order to find the decimal form of a percent, we divide it by .  

Find the tax:

 

Therefore the sales tax added to the original price is $

The final cost of the jeans is $.

 

Example Question #851 : Numbers And Operations

At a pet store, there are 12 dogs and 8 cats. The following week, the number of dogs increases by 25%, while the number of cats decreases by 25%. What is the total number of animals at the store the following week?

Assume the store only sells dogs and cats.

Possible Answers:

Correct answer:

Explanation:

If the population of dogs increases by 25%, then we first find 25% of 12 (which is 3) and add the 3 to 12. This gives us 15 dogs.

If the population of cats decreases by 25%, then we find 25% of 8 (which is 2), and subtract if from 8. This gives us 6. 

Now that we know the final individual numbers of dogs and cats, we can add them to find the final answer.

Example Question #11 : How To Find The Whole From The Part With Percentage

Tom the baker made  blueberry muffins on Tuesday, and Stan the baker made and  muffins that day. On Wednesday, each baker decided to increase his production of blueberry muffins by . What is the average of blueberry muffins that Tom and Stan baked on Wednesday?

Possible Answers:

Correct answer:

Explanation:

Tom made  blueberry muffins on Tuesday, and Stan made and  muffins that day. On Wednesday, each baker decided to increase his production of blueberry muffins by .

Given that  of  is , the number of muffins made by Tom on Wednesday would be 

Given that  of  is , the number of muffins made by Stan on Wednesday would be 

The average is calculated by adding numbers in a list together, and then dividing by the number of items in that list. This gives us:

Example Question #13 : How To Find The Whole From The Part With Percentage

10 percent of a cake weights 20 ounces. The entire cake is cut into 8 pieces. How many ounces does each piece weigh?

Possible Answers:

 ounces

 ounces

 ounces

 ounces

Correct answer:

 ounces

Explanation:

If 10 percent of the cake weights 20 ounces, then the entire cake will weigh 200 ounces, because 10 times 20 is 200. 

If the cake has 8 slices, then each slice will weigh (in ounces) 200 divided by 8. 200 divided by 8 is 25; therefore, 25 ounces is the correct answer. 

Example Question #13 : How To Find The Whole From The Part With Percentage

There are 12 sopranos in the Red Street Choir.  If sopranos are 40% of the choir, how many total members make up the Red Street Choir?

Possible Answers:

Correct answer:

Explanation:

When given a part, you can use a percentage to determine the whole by converting the percentage to a decimal and dividing the part by that number. 

Example Question #11 : How To Find The Whole From The Part With Percentage

If you have  of a quiz completed after  questions, how long is the quiz?

Possible Answers:

Correct answer:

Explanation:

To find a part of a whole with a percentage, you multiply the whole by the percent.  

To find the opposite, you divide the part by the percent so it would be .  

This is equal to 

 or .

Example Question #852 : Numbers And Operations

There are 8 pieces of pizza. If Justin at 25% of the pizza, how many pieces did he have?

Possible Answers:

Correct answer:

Explanation:

25% is equivalent to the fraction

 and can then be reduced to 

 which is equivalent to 

,

meaning that if Justin ate 25% of the pizza, he ate 2 of the 8 pieces.

Example Question #1 : Percentages

 is  of what number?

Possible Answers:

Correct answer:

Explanation:

If  is  of a number, , then we can set up an equation. First, we convert to a decimal, . Then, we can formulate the equation below.

Solve for by dividing both sides of the equation by .

Example Question #1 : How To Find The Part From The Whole With Percentage

Which is larger?

a. 10% of 90

b. 5% of 160

c. 20% of 50

d. 30% of 40

Possible Answers:

Correct answer:

Explanation:

First find the percentage amount for each choice by multiplying the number by the percentage amount

a.

b.

c.

d.

Then compare the amounts to find the largest.

The answer is (d) 12.

Example Question #1 : How To Find The Part From The Whole With Percentage

A laptop computer is on sale for 40% less than the original price. If the original price is $345.00, what is the laptop's current sale price?

 

 

Possible Answers:

Correct answer:

Explanation:

First, multiply the original price by the sale percentage:

Then, subtract that amount from the original price to get the sale price:

.

The laptop's current sale price is 

Learning Tools by Varsity Tutors