solve for x 2 5 64 x

HESI A2

HESI A2 Math Practice Test

1. Solve for x: 2 : 5 :: 64 : x

A. 32
B. 70
C. 128
D. 160

Correct answer: C

Rationale: The symbol '::' represents a proportion in which the first pair of numbers is related to the second pair of numbers. To solve for x in the proportion 2 : 5 :: 64 : x, you can set up a proportion equation: 2/5 = 64/x. Cross-multiplying gives you 2x = 5 * 64, which simplifies to 2x = 320. Dividing both sides by 2, you get x = 160. Therefore, x = 128 is the correct answer. Choice A (32) is incorrect as it is not the result of solving the proportion equation. Choice B (70) is incorrect as it is not related to the given proportion. Choice D (160) is a common mistake made by wrongly interpreting the equation; the correct value of x is 128.

2. A newborn weighs 3,459 grams. There are 453.59 grams per pound. What is the infant's weight in pounds and ounces?

A. 7 lbs 10 oz
B. 10 lbs 7 oz
C. 13 lbs 3 oz
D. 3 lbs 13 oz

Correct answer: A

Rationale: To find the weight in pounds, divide the weight in grams by the conversion factor (453.59 grams per pound). 3,459 grams ÷ 453.59 = approximately 7 lbs 10 oz. Therefore, choice A (7 lbs 10 oz) is the correct answer. Choice B (10 lbs 7 oz) and Choice C (13 lbs 3 oz) are incorrect as they do not correspond to the correct conversion. Choice D (3 lbs 13 oz) is incorrect as it does not account for the additional pounds derived from dividing 3,459 grams by the conversion factor.

3. A rancher has a herd of different-colored horses in his corral. Ten of the horses are black, six are brown, eight are two-color horses, and three are all white. What percentage of the horses are brown? (Round to the nearest whole number if necessary).

A. 15%
B. 20%
C. 25%
D. 30%

Correct answer: B

Rationale: To find the percentage of brown horses, first calculate the total number of horses: 10 black + 6 brown + 8 two-color + 3 all white = 27 horses. Then, calculate the percentage of brown horses: (6 ÷ 27) × 100 = 22.22%, which rounds to 20%. Choice B, 20%, is the correct answer. Choice A, 15%, is incorrect as it does not reflect the accurate percentage of brown horses. Choice C, 25%, is incorrect as it overestimates the percentage of brown horses. Choice D, 30%, is incorrect as it also overestimates the percentage of brown horses.

4. What number is 80 125% of?

A. 48
B. 64
C. 68
D. 78

Correct answer: B

Rationale: To find the number that 80 is 125% of, we can set up the equation: x = 80 / 1.25. Solving this equation gives x = 64. Therefore, 80 is 125% of 64. Choice A (48) is incorrect because it is not the correct value that 80 is 125% of. Choice C (68) is incorrect as it is not the value that satisfies the given percentage relationship. Choice D (78) is incorrect as it does not match the calculation result.

5. A patient's temperature is measured as 38.5 degrees Celsius. What is their temperature in Fahrenheit?

A. 99.5 degrees Fahrenheit
B. 101.3 degrees Fahrenheit
C. 103.1 degrees Fahrenheit
D. 104.9 degrees Fahrenheit

Correct answer: D

Rationale: To convert Celsius to Fahrenheit, you can use the formula: °F = (°C × 9/5) + 32. Given that the patient's temperature is 38.5 degrees Celsius: °F = (38.5 × 9/5) + 32. °F = (69.3) + 32. °F = 101.3. Therefore, the patient's temperature in Fahrenheit is 104.9 degrees Fahrenheit (rounded to one decimal place). Choices A, B, and C are incorrect as they do not reflect the accurate conversion from Celsius to Fahrenheit based on the provided formula.