if x 2 and m 3 evaluate xm 2m

HESI A2

HESI A2 Practice Test Math

1. If x = -2 and m = -3, evaluate: xm - 2m

A. 12
B. 6
C. 8
D. 10

Correct answer: A

Rationale: Substitute x = -2 and m = -3 into the expression: (-2) * (-3) - 2 * (-3) = 6 + 6 = 12. Therefore, the correct answer is 12. The mistake in the other choices lies in the calculation. Choice B, 6, is the result of adding the two terms instead of subtracting the second term from the first. Choice C, 8, and Choice D, 10, are also incorrect as they do not follow the correct calculation process.

2. 7:5=91:x. Find x.

A. x=65
B. x=55
C. x=75
D. x=85

Correct answer: A

Rationale: To solve the proportion 7:5=91:x, cross multiply to get 7x = 5 * 91. Then, solve for x by dividing both sides by 7, which gives x = 65. Therefore, the correct answer is x=65. Choice B, x=55, is incorrect because it does not satisfy the proportion equation. Choices C and D, x=75 and x=85, are also incorrect as they do not match the calculated value of x when the proportion is solved.

3. If 9 out of 75 band members missed practice, what percentage of band members missed practice?

A. 10%
B. 12%
C. 15%
D. 18%

Correct answer: B

Rationale: To calculate the percentage of band members who missed practice, divide the number of members who missed practice (9) by the total number of band members (75) and multiply by 100. (9/75) * 100 = 12%. Therefore, 12% of the band members missed practice. Choice A (10%) is incorrect because it is not the correct calculation result. Choices C (15%) and D (18%) are also incorrect as they do not reflect the accurate percentage of band members who missed practice.

4. A pressure vessel has a cylindrical body (diameter 10cm, height 20cm) with hemispherical ends (same diameter as the cylinder). What is its total surface area?

A. 785 sq cm
B. 1130 sq cm
C. 1570 sq cm
D. 2055 sq cm

Correct answer: D

Rationale: To find the total surface area, we need to calculate the surface area of the cylindrical body and both hemispherical ends separately. The surface area of the cylinder is the sum of the lateral surface area (2πrh) and the area of the two circular bases (2πr^2). For the hemispheres, the surface area of one hemisphere is (2πr^2), so for two hemispheres, it would be (4πr^2). Given that the diameter of the cylinder and hemispherical ends is 10cm, the radius (r) is 5cm. Calculating the individual surface areas: Cylinder = 2π(5)(20) + 2π(5)^2 = 200π + 50π = 250π. Hemispheres = 4π(5)^2 = 100π. Adding these together gives a total surface area of 250π + 100π = 350π cm^2, which is approximately equal to 2055 sq cm. Therefore, the correct answer is D. Choice A (785 sq cm) is incorrect as it is significantly lower than the correct calculation. Choices B (1130 sq cm) and C (1570 sq cm) are also incorrect as they do not reflect the accurate surface area calculation for the given dimensions.

5. Two buildings in downtown Chicago stand across the river. The first building is 1,700 feet tall and casts a shadow of 525 feet. If the second building is 1,450 feet tall, how long will its shadow be?

A. 478 feet
B. 455 feet
C. 448.5 feet
D. 450 feet

Correct answer: C

Rationale: To find the shadow of the second building, we use the ratio of heights to shadows: 1,700/525 = 1,450/x. Solving for x gives x = (525 × 1,450)/1,700 = 448.5. Therefore, the shadow of the second building will be approximately 448.5 feet long. Choice A (478 feet) is incorrect because it is not the result of the correct calculation. Choice B (455 feet) is incorrect as it does not match the accurate answer obtained through the calculation. Choice D (450 feet) is incorrect as it does not reflect the correct length of the shadow of the second building.