multiply 54 45

HESI A2

HESI A2 Math Practice Test

1. Multiply: 54 × 45. Express the result in decimal form.

A. 0.0243
B. 0.243
C. 2.43
D. 24.3

Correct answer: D

Rationale: To multiply 54 by 45, you should multiply the two numbers together: 54 x 45 = 2430. The decimal point is placed after counting the total decimal places in the numbers being multiplied. As there are no decimal places in the numbers 54 and 45, the result is 2430, which is correctly expressed as 24.3 when considering the decimal point placement. Choice A (0.0243) and Choice B (0.243) are incorrect as they represent fractions of 2430. Choice C (2.43) is incorrect as it incorrectly places the decimal point one place before the actual result.

2. What number is 15, if it is 20% of that number?

A. 3
B. 45
C. 75
D. 300

Correct answer: B

Rationale: To find the number that 15 is 20% of, we set up the equation: x * 0.20 = 15. Solving for x, we get x = 15 / 0.20 = 75. Therefore, 15 is 20% of 75. Choice A, 3, is too small to be 20% of 15. Choice C, 75, is the result of the correct calculation. Choice D, 300, is too large to be 20% of 15.

3. A lampshade is shaped like a frustum of a cone, with base diameters of 20cm and 10cm and a height of 15cm. What is its volume?

A. 625 cu cm
B. 1250 cu cm
C. 1875 cu cm
D. 2500 cu cm

Correct answer: C

Rationale: To find the volume of the frustum of a cone, divide it into two cones and calculate their volumes separately. The formula for the volume of a cone frustum involves the radii of both bases and the height. The volume of the frustum cone can be calculated as V = 1/3 * π * h * (R^2 + r^2 + R * r), where R is the larger radius, r is the smaller radius, and h is the height. Substituting the values, V = 1/3 * π * 15 * (10^2 + 20*10 + 20^2) = 1875 cu cm. Therefore, the correct answer is 1875 cu cm. Choice A, B, and D are incorrect as they do not correspond to the correct calculation of the frustum's volume.

4. Divide: 5,117 ÷ 31 =

A. 109 r3
B. 115 r14
C. 133 r5
D. 165 r2

Correct answer: D

Rationale: When dividing 5,117 by 31, the quotient is 165 with a remainder of 2. The correct answer is 165 r2. Choices A, B, and C are incorrect as they do not reflect the correct division result. Choice A is close but has the wrong remainder. Choices B and C have incorrect quotients and remainders, making them inaccurate. Therefore, the correct answer is D, 165 r2.

5. When a die is rolled, what is the probability of rolling an odd number?

A. 16.67%
B. 33.33%
C. 75%
D. 50%

Correct answer: D

Rationale: When a die is rolled, there are 3 odd numbers (1, 3, 5) out of a total of 6 possible outcomes. The probability of rolling an odd number is calculated by dividing the number of favorable outcomes (3) by the total number of outcomes (6), resulting in a probability of 3/6 or 50%. Therefore, the correct answer is D. Choices A, B, and C are incorrect because they do not reflect the correct probability calculation for rolling an odd number on a standard six-sided die.