express as a percent

HESI A2

HESI A2 Math Portion

1. Express 4/5 as a percent.

A. 20%
B. 40%
C. 50%
D. 80%

Correct answer: D

Rationale: To convert a fraction to a percentage, you multiply the fraction by 100. To express 4/5 as a percent, you perform the calculation 4/5 * 100 = 80%. Therefore, the correct answer is D, 80%. Choices A, B, and C are incorrect as they do not represent the correct conversion of 4/5 to a percentage.

2. Compare: 0.045 is _____ to 0.054.

A. Greater than
B. Less than
C. Less than or equal to
D. Equal

Correct answer: B

Rationale: The correct answer is B. When comparing 0.045 and 0.054, 0.045 is less than 0.054. Therefore, the correct relation is 'Less than.' Choice A ('Greater than') is incorrect because 0.045 is not greater than 0.054. Choice C ('Less than or equal to') is incorrect because 0.045 is strictly less than 0.054, not less than or equal to. Choice D ('Equal') is incorrect because 0.045 and 0.054 are not equal.

3. A lab needs 200ml of a 5% salt solution. They only have a 10% solution. How much 10% solution and water should be mixed?

A. 100ml 10% solution, 100ml water
B. 150ml 10% solution, 50ml water
C. 160ml 10% solution, 40ml water
D. 200ml 10% solution, 0ml water

Correct answer: B

Rationale: Rationale: 1. Let x be the volume of the 10% solution needed and y be the volume of water needed. 2. The total volume of the final solution is 200ml, so x + y = 200. 3. The concentration of the final solution is 5%, so the amount of salt in the final solution is 0.05 * 200 = 10g. 4. The amount of salt in the 10% solution is 0.1x, and the amount of salt in the water is 0, so the total amount of salt in the final solution is 0.1x. 5. Since the total amount of salt in the final solution is 10g, we have 0.1x = 10. 6. Solving for x, we get x = 100ml. 7. Substituting x =

4. How many liters are in 2500 milliliters?

A. 2.5 liters
B. 1.5 liters
C. 3.5 liters
D. 0.25 liters

Correct answer: A

Rationale: The correct answer is A: 2.5 liters. There are 1,000 milliliters in a liter. To convert 2,500 milliliters to liters, you need to divide by 1,000: 2,500 / 1,000 = 2.5 liters. Choice B (1.5 liters) is incorrect because it miscalculates the conversion. Choice C (3.5 liters) is incorrect as it overestimates the conversion. Choice D (0.25 liters) is incorrect as it underestimates the conversion. Therefore, the correct conversion is 2.5 liters.