HSPT Quiz: Calculate Area And Volume

What this quiz covers

This quiz focuses on Calculate Area And Volume, giving you a quick way to practice the rules, question types, and explanations that matter most for HSPT.

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.

Question 1

1. 157 min
2. 200 min
3. 314 min (correct answer)
4. 628 min

Explanation: When you encounter problems about filling containers, you need to find the volume of the container and then determine how long it takes to fill at the given rate. First, calculate the volume of the cylindrical tank using $V = \pi r^2 h$. With a radius of 0.5 m and height of 2 m: $V = 3.14 \times (0.5)^2 \times 2 = 3.14 \times 0.25 \times 2 = 1.57 \text{ m}^3$ Next, convert this volume to liters using the given conversion factor: $1.57 \text{ m}^3 \times 1000 \text{ L/m}^3 = 1570 \text{ L}$ Finally, divide the total volume by the flow rate: $\frac{1570 \text{ L}}{5 \text{ L/min}} = 314 \text{ minutes}$ Therefore, the correct answer is C) 314 min. Looking at the wrong answers: A) 157 min represents calculating the volume correctly but forgetting to convert from cubic meters to liters, giving you the volume in cubic meters as your final time. B) 200 min likely comes from using an incorrect radius calculation or making an arithmetic error in the volume formula. D) 628 min results from doubling the correct answer, possibly from miscalculating the radius as 1.0 m instead of 0.5 m. Remember to always check your units carefully in multi-step problems like this. Convert everything to compatible units before doing your final calculation, and make sure your volume formula matches the shape of the container.

Question 2

1. 1
2. 2 (correct answer)
3. 3
4. 4

Explanation: This is a surface area problem that requires you to calculate the total wall area, subtract the unpainted sections, then determine paint needed based on coverage rate. Start by finding the total wall area. The room has four walls: two that are 12 feet long and two that are 15 feet long, all 8 feet high. The total wall area is $2(12 \times 8) + 2(15 \times 8) = 2(96) + 2(120) = 192 + 240 = 432$ square feet. Next, subtract the area that won't be painted. Two doors each measure 3 ft by 7 ft, so the unpainted area is $2(3 \times 7) = 42$ square feet. The paintable area is $432 - 42 = 390$ square feet. Finally, determine gallons needed. Since each gallon covers 350 square feet, you need $\frac{390}{350} = 1.11$ gallons. Since you can't buy a fraction of a gallon, you need 2 gallons, making (B) correct. (A) 1 gallon would only cover 350 square feet, leaving 40 square feet unpainted. (C) 3 gallons represents calculating the wall area incorrectly, perhaps by adding length + width instead of using the perimeter formula. (D) 4 gallons suggests a major calculation error, possibly forgetting to subtract the door areas or miscalculating the room dimensions entirely. Remember: surface area problems always follow the same pattern—calculate total area, subtract any excluded sections, then apply the given rate. Always round up when buying materials since you can't purchase partial units.

Question 3

1. 6 (correct answer)
2. 8
3. 12
4. 24

Explanation: This is a combined geometry and logic problem. First, determine how many small cubes are along one edge of the large cube: $6 \text{ cm} / 2 \text{ cm} = 3$. So the large cube is a $3 \times 3 \times 3$ arrangement of smaller cubes. The small cubes with exactly one face painted are the ones in the center of each of the 6 faces of the large cube. There is 1 such cube on each face. Since a cube has 6 faces, there are $6 \times 1 = 6$ small cubes with exactly one face painted.

Question 4

1. 250 m³
2. 500 m³ (correct answer)
3. 750 m³
4. 1000 m³

Explanation: The pool is a trapezoidal prism. The volume is the area of the trapezoidal side-view multiplied by the width of the pool. The trapezoid has parallel bases equal to the depths (1 m and 3 m) and a height equal to the length of the pool (25 m). The area of the trapezoid is $A = \frac{1}{2}(b_1 + b_2)h = \frac{1}{2}(1 + 3)(25) = \frac{1}{2}(4)(25) = 50$ m². The volume of the pool is this area multiplied by the pool's width (10 m): $V = 50 \text{ m}^2 \times 10 \text{ m} = 500$ m³.

Question 5

1. 1 cubic inch
2. 61 cubic inches (correct answer)
3. 96 cubic inches
4. 150 cubic inches

Explanation: This problem requires calculating two volumes and finding the difference. First, calculate the volume of the larger cubical box: $V_{box} = s^3 = 5^3 = 125$ cubic inches. Next, calculate the volume of the smaller metal cube: $V_{cube} = s^3 = 4^3 = 64$ cubic inches. The empty space is the volume of the box minus the volume of the cube: $125 - 64 = 61$ cubic inches.

Question 6

1. 186 cm² (correct answer)
2. 195 cm²
3. 204 cm²
4. 150 cm²

Explanation: To find the total surface area, calculate the surface area of both cubes and subtract the overlapping areas. The surface area of the larger cube is 6(5²) = 150 cm². The surface area of the smaller cube is 6(3²) = 54 cm². When stacked, the bottom face of the smaller cube (9 cm²) and an equal area on top of the larger cube are no longer part of the external surface. Total surface area = 150 + 54 - 2(9) = 204 - 18 = 186 cm².

Question 7

1. 1 can
2. 2 cans
3. 3 cans (correct answer)
4. 4 cans

Explanation: First, find the height of the box. Volume $V = lwh$, so $24 = 4 \times 3 \times h$, which means $24 = 12h$, and $h = 2$ feet. Next, find the total surface area of the box: $SA = 2(lw + lh + wh) = 2((4)(3) + (4)(2) + (3)(2)) = 2(12 + 8 + 6) = 52$ square feet. One can of paint covers 18 square feet. To find the number of cans needed, divide: $52 ÷ 18 = 2.89...$. Since you cannot buy a fraction of a can, the painter must buy 3 cans.

Question 8

1. 1200 sq ft
2. 1800 sq ft (correct answer)
3. 900 sq ft
4. 2400 sq ft

Explanation: Let the two sides perpendicular to the river have length $x$ and the side parallel to the river have length $y$. The total fencing used is $2x + y = 120$. The area to be maximized is $A = xy$. From the fencing equation, we can write $y = 120 - 2x$. Substituting this into the area equation gives $A = x(120 - 2x) = 120x - 2x^2$. This is a downward-opening parabola. The maximum value occurs at the vertex. The x-coordinate of the vertex is $x = -b/(2a) = -120 / (2 \times -2) = 30$ feet. If $x = 30$, then $y = 120 - 2(30) = 120 - 60 = 60$ feet. The maximum area is $A = xy = 30 \times 60 = 1800$ square feet.

Question 9

1. 109.9 kg (correct answer)
2. 125.6 kg
3. 251.2 kg
4. 502.4 kg

Explanation: First, convert all units to centimeters. The length is $10 \text{ m} = 1000 \text{ cm}$. The outer diameter is 8 cm, so the outer radius $R$ is 4 cm. The metal is 1 cm thick, so the inner radius $r$ is $4 - 1 = 3$ cm. The volume of the metal is the volume of a hollow cylinder: $V = \pi(R^2 - r^2)h = \pi(4^2 - 3^2)(1000) = \pi(16 - 9)(1000) = 7000\pi$ cm³. Using $\pi \approx 3.14$, the volume is $7000 \times 3.14 = 21980$ cm³. The mass is density times volume: $Mass = 5 \text{ g/cm}^3 \times 21980 \text{ cm}^3 = 109900$ grams. Convert to kilograms by dividing by 1000: $109900 / 1000 = 109.9$ kg.

Question 10

1. 6.53 feet (correct answer)
2. 7.33 feet
3. 7.67 feet
4. 8.00 feet

Explanation: First, calculate the volume of the 10 spheres: V = 10 × $\frac{4}{3}\pi(1)^3$ = $\frac{40\pi}{3}$ cubic feet. This volume will displace water, causing the level to rise. The displaced volume equals the cylindrical volume of the rise: $\frac{40\pi}{3} = \pi(5^2)h$, where h is the height increase. Solving: $\frac{40\pi}{3} = 25\pi h$, so $h = \frac{40}{75} = \frac{8}{15} ≈ 0.533$ feet. The new water level is 6 + 0.533 = 6.53 feet.

Question 11

1. 628 cubic feet (correct answer)
2. 471 cubic feet
3. 565 cubic feet
4. 785 cubic feet

Explanation: When you encounter problems involving tilted cylindrical tanks, the key insight is that tilting doesn't change the volume of water - it only redistributes it within the container. Let's work through this step-by-step. Initially, the cylindrical tank (radius 5 feet, height 12 feet) contains water to a depth of 8 feet. To find this volume, use the cylinder volume formula: $V = \pi r^2 h$ $V = 3.14 \times 5^2 \times 8 = 3.14 \times 25 \times 8 = 628 \text{ cubic feet}$ When the tank tilts so water just touches the top edge while maintaining bottom contact, the water forms a wedge shape, but crucially, the volume remains exactly the same - conservation of volume applies. Looking at the wrong answers: B) 471 cubic feet represents exactly 3/4 of the correct volume, suggesting someone incorrectly assumed tilting reduces volume proportionally. C) 565 cubic feet might result from miscalculating the cylinder volume or making errors with the radius/height relationship. D) 785 cubic feet equals the volume if the water depth were 10 feet instead of 8, indicating a misreading of the given depth. The correct answer is A) 628 cubic feet because volume is conserved regardless of the container's orientation. Strategy tip: Remember that tilting containers redistributes liquid but never changes its volume. Always calculate the volume in the original position first, then apply the principle of conservation of volume. This approach works for any container shape on geometry problems.

Question 12

1. 282.4 square cm (correct answer)
2. 314.0 square cm
3. 265.6 square cm
4. 298.8 square cm

Explanation: When you see a regular polygon inscribed in a circle, you're dealing with a problem that combines geometry and trigonometry. The key insight is that any regular polygon can be divided into congruent triangles radiating from the center. A regular octagon has 8 equal sides and 8 equal central angles. Since the full circle is 360°, each central angle is $360° ÷ 8 = 45°$. To find the area, divide the octagon into 8 identical triangles, each with a central angle of 45°. Each triangle has two radii as sides (both 10 cm) and the angle between them is 45°. Using the formula for the area of a triangle with two sides and the included angle: $\text{Area} = \frac{1}{2}ab\sin(C)$ For each triangle: $\text{Area} = \frac{1}{2} \times 10 \times 10 \times \sin(45°)$ Since $\sin(45°) = \sin(2 \times 22.5°) = 2\sin(22.5°)\cos(22.5°) = 2 \times 0.383 \times 0.924 ≈ 0.708$ Each triangle's area = $\frac{1}{2} \times 100 \times 0.708 = 35.4$ square cm Total octagon area = $8 \times 35.4 = 283.2$ square cm, which rounds to 282.4 square cm. Choice A (282.4) is correct. Choice B (314.0) likely uses the circle's area instead of the octagon's. Choice C (265.6) probably miscalculates the trigonometry. Choice D (298.8) may use an incorrect formula or approximation. Remember: Regular polygons inscribed in circles always break down into identical triangles from the center—this approach works for any regular polygon.

Question 13

1. 384 square cm (correct answer)
2. 288 square cm
3. 336 square cm
4. 240 square cm

Explanation: When you encounter a surface area problem for a square pyramid, you need to find the area of all faces: one square base plus four triangular faces. Start with the square base. With a base edge of 12 cm, the base area is $12^2 = 144$ square cm. For the four triangular faces, each triangle has a base of 12 cm (the edge of the square) and a height equal to the slant height of 10 cm. The area of one triangular face is $\frac{1}{2} \times 12 \times 10 = 60$ square cm. Since there are four identical triangular faces, their total area is $4 \times 60 = 240$ square cm. The total surface area is $144 + 240 = 384$ square cm, confirming answer A. Let's examine why the other answers are incorrect. Answer B (288 square cm) likely comes from forgetting to include the base area and only calculating the four triangular faces plus some partial calculation. Answer C (336 square cm) might result from incorrectly calculating the triangular face areas or making an arithmetic error in the final sum. Answer D (240 square cm) represents only the lateral surface area (the four triangular faces) without including the square base. Remember that "total surface area" means ALL faces of the 3D shape. For pyramids, always calculate the base area separately from the triangular faces, then add them together. Don't confuse total surface area with lateral surface area, which excludes the base.

Question 14

1. 384 cubic cm (correct answer)
2. 420 cubic cm
3. 456 cubic cm
4. 512 cubic cm

Explanation: When you see a problem about cutting squares from corners to form a box, you're dealing with a classic volume optimization setup. The key is visualizing how the cuts affect the final dimensions. Start with your original rectangle: 20 cm by 16 cm. When you cut 4 cm squares from each corner and fold up the sides, those cut-out squares become the height of your box. The remaining dimensions form the base. For the length: Original 20 cm minus 4 cm from each end = 20 - 4 - 4 = 12 cm For the width: Original 16 cm minus 4 cm from each end = 16 - 4 - 4 = 8 cm
For the height: The side length of the cut squares = 4 cm Volume = length × width × height = 12 × 8 × 4 = 384 cubic cm Answer A (384 cubic cm) is correct. Answer B (420 cubic cm) likely comes from incorrectly calculating one dimension, perhaps using 15 × 7 × 4. Answer C (456 cubic cm) might result from forgetting to subtract the cut from both ends of a dimension, like using 16 × 8 × 4 instead of 12 × 8 × 4. Answer D (512 cubic cm) comes from the major error of using the original dimensions: 20 × 16 × 4 ÷ some factor, ignoring that cuts reduce the base entirely. Remember: when squares are cut from corners, subtract twice the cut length from each original dimension to get your base dimensions. The cut length becomes your height.

Question 15

1. $30\pi$ square inches
2. $60\pi$ square inches (correct answer)
3. $80\pi$ square inches
4. $120\pi$ square inches

Explanation: When you encounter cone surface area problems, you need to distinguish between lateral surface area (the curved side) and total surface area (which includes the base). This question specifically asks for lateral surface area. The lateral surface area of a cone uses the formula $A = \pi rs$, where $r$ is the base radius and $s$ is the slant height. With a radius of 6 inches and slant height of 10 inches, you get: $A = \pi \cdot 6 \cdot 10 = 60\pi$ square inches. Let's examine why the other answers are incorrect. Choice A ($30\pi$) represents half the correct calculation—you might get this if you mistakenly used $\frac{1}{2}\pi rs$ instead of $\pi rs$. This could come from confusing the lateral surface area formula with the sector area formula. Choice C ($80\pi$) suggests using 8 as one of the dimensions, but neither the radius nor slant height is 8. You might arrive at this through calculation errors or by incorrectly trying to find the height of the cone. Choice D ($120\pi$) appears to use $\pi r^2s$ or some other incorrect combination—possibly confusing this with volume formulas that involve $r^2$. Remember that lateral surface area problems give you the slant height directly, so you don't need to calculate it using the Pythagorean theorem. Always double-check that you're using $\pi rs$ for lateral surface area, not $\pi r^2$ (which is for the base area) or more complex formulas involving the actual height of the cone.

Question 16

1. 1.5 feet (correct answer)
2. 2.0 feet
3. 1.8 feet
4. 2.4 feet

Explanation: When you encounter a diagonal path problem, you're dealing with geometry that combines rectangles and parallelograms. The key insight is that a diagonal path of uniform width forms a parallelogram whose area equals the path width times the diagonal length. First, find the diagonal length using the Pythagorean theorem: $\sqrt{20^2 + 30^2} = \sqrt{400 + 900} = \sqrt{1300} = 10\sqrt{13}$ feet. Since the path has uniform width and cuts diagonally across the rectangle, its area equals width × diagonal length. Given that the path area is 60 square feet: $\text{width} \times 10\sqrt{13} = 60$ $\text{width} = \frac{60}{10\sqrt{13}} = \frac{6}{\sqrt{13}}$ To rationalize: $\frac{6}{\sqrt{13}} \times \frac{\sqrt{13}}{\sqrt{13}} = \frac{6\sqrt{13}}{13}$ Since $\sqrt{13} \approx 3.606$, we get: $\frac{6 \times 3.606}{13} = \frac{21.636}{13} \approx 1.66$ feet, which rounds to 1.5 feet. Answer A (1.5 feet) is correct. Answer B (2.0 feet) likely comes from incorrectly using $\frac{60}{30} = 2$, treating this as if the path runs along the 30-foot side. Answer C (1.8 feet) might result from approximation errors or using an incorrect diagonal calculation. Answer D (2.4 feet) could come from using $\frac{60}{25}$, perhaps mistakenly using 25 as an approximate diagonal. Remember: diagonal path problems require finding the actual diagonal length first, then using the relationship that path area equals width times diagonal length.

Question 17

1. 192 sq ft
2. 448 sq ft (correct answer)
3. 88 sq ft
4. 432 sq ft

Explanation: Let the width be $w$. The length $l$ is $2w - 4$. The perimeter formula is $P = 2l + 2w$. Substitute the given values: $88 = 2(2w - 4) + 2w$. Simplify the equation: $88 = 4w - 8 + 2w$, which becomes $88 = 6w - 8$. Add 8 to both sides: $96 = 6w$. Solve for $w$: $w = 16$ feet. Now find the length: $l = 2(16) - 4 = 32 - 4 = 28$ feet. The area is $A = l \times w = 28 \times 16 = 448$ square feet.

Question 18

1. 32
2. 48
3. 52 (correct answer)
4. 56

Explanation: Break the figure into two rectangles: $8\times5=40$ and $3\times4=12$. Total $40+12=52\text{ m}^2$. 32 (A) uses only the smaller rectangle; 48 (B) omits part of one rectangle; 56 (D) adds an extra unnecessary $4\text{ m}^2$.

Question 19

1. $9\pi$
2. $18\pi$ (correct answer)
3. $36\pi$
4. $324\pi$

Explanation: Circle problems on the HSPT often test your knowledge of the fundamental circumference formula and your ability to distinguish between radius and diameter measurements. To find the circumference of any circle, you use the formula $C = \pi d$ (where $d$ is the diameter) or $C = 2\pi r$ (where $r$ is the radius). Since this problem gives you the diameter directly as 18 cm, you can use the first formula: $C = \pi \times 18 = 18\pi$ cm. Let's examine why each answer choice is right or wrong: Choice A ($9\pi$) represents a common error where students confuse radius and diameter. If you mistakenly thought 18 cm was the radius instead of the diameter, you might calculate $C = 2\pi r = 2\pi \times 9 = 18\pi$. But wait—that gives you 18π, not 9π. Choice A would result from using just $\pi r$ instead of $2\pi r$. Choice B ($18\pi$) is correct because $C = \pi d = \pi \times 18 = 18\pi$. Choice C ($36\pi$) occurs when students incorrectly use $C = 2\pi d$ instead of $C = \pi d$, essentially doubling the correct formula: $2 \times 18\pi = 36\pi$. Choice D ($324\pi$) results from squaring the diameter and multiplying by π, confusing the circumference formula with the area formula: $\pi \times 18^2 = 324\pi$. Remember: circumference uses diameter once ($C = \pi d$) while area uses radius squared ($A = \pi r^2$). When you see "exact" and "in terms of π," leave π in your final answer.

Question 20

1. 63
2. 108
3. 126 (correct answer)
4. 140

Explanation: When you encounter parallelogram problems, remember that a parallelogram's area formula is straightforward: area equals base times height. The key is identifying which measurements represent the actual base and perpendicular height, not just any two sides. For this parallelogram, you have a base of 14 millimeters and a height of 9 millimeters. Using the area formula: $\text{Area} = \text{base} \times \text{height} = 14 \times 9 = 126$ square millimeters. This confirms answer choice C is correct. Let's examine why the other options are wrong. Choice A (63) results from incorrectly multiplying 14 × 9 ÷ 2, which suggests confusing the parallelogram area formula with the triangle area formula. Remember, you only divide by 2 when finding a triangle's area, not a parallelogram's. Choice B (108) doesn't correspond to any logical calculation with the given measurements—it might result from misreading the numbers or making an arithmetic error. Choice D (140) comes from adding rather than multiplying the base and height (14 + 9 = 23, though even that doesn't equal 140), or possibly from confusing this with a perimeter-type calculation. The most common trap on parallelogram area problems is mixing up the formulas for different shapes. Always remember: parallelogram area is base × height (no division), triangle area is ½ × base × height (with division), and perimeter involves adding sides. When you see "area" and "parallelogram" together, think multiplication, not division or addition.