change the percent to a decimal 38

HESI A2

Practice HESI A2 Math Test

1. Convert the percentage to a decimal: 38%

A. 3.8
B. 0.38
C. 0.038
D. 38.0

Correct answer: B

Rationale: To convert a percentage to a decimal, you divide the percentage by 100. Therefore, 38% as a decimal is 0.38 (38 ÷ 100 = 0.38). Choice A, 3.8, is incorrect as it is equivalent to 380%. Choice C, 0.038, is incorrect as it represents 3.8%. Choice D, 38.0, is incorrect as it is still in percentage form.

2. 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.

3. A birdbath has a hemispherical bowl with a diameter of 30cm. What is its volume?

A. 675 cu cm
B. 1350 cu cm
C. 2700 cu cm
D. 4050 cu cm

Correct answer: C

Rationale: To find the volume of a hemispherical bowl, we use half the formula for a sphere's volume: (2/3) * π * (radius)^3. Given the diameter is 30cm, the radius is half of that, which is 15cm. Substitute the radius into the formula: (2/3) * π * (15cm)^3 ≈ 2700 cu cm. Therefore, the correct volume is approximately 2700 cu cm. Choices A, B, and D are incorrect as they do not correctly calculate the volume of the hemispherical bowl.

4. Convert 7 grams to milligrams.

A. 700 mg
B. 7,000 mg
C. 70 mg
D. 0.007 mg

Correct answer: B

Rationale: To convert grams to milligrams, you need to multiply by 1,000 since there are 1,000 milligrams in a gram. Therefore, 7 grams x 1,000 = 7,000 mg. Choice A (700 mg) is incorrect as it represents 700 grams, not milligrams. Choice C (70 mg) is incorrect as it implies that 7 grams is equivalent to 70 milligrams, which is inaccurate. Choice D (0.007 mg) is also incorrect since it represents a fraction of a milligram, significantly less than the original 7 grams.

5. Convert this military time to regular time: 1010 hours.

A. 10:10 A.M.
B. 10:10 P.M.
C. 1:01 A.M.
D. 1:01 P.M.

Correct answer: A

Rationale: To convert military time to regular time, we can drop the first two digits if they are less than 12. 1010 hours can be converted to 10:10 A.M. because it is before noon (12:00 P.M.). Military time operates on a 24-hour clock system, with 0000 hours indicating midnight and 1200 hours representing noon. Therefore, in this case, 1010 corresponds to 10:10 A.M. Choice B (10:10 P.M.) is incorrect as 1010 hours is in the morning, not the evening. Choices C (1:01 A.M.) and D (1:01 P.M.) are incorrect as they do not match the given military time of 1010 hours.