a lab needs 200ml of a 5 salt solution they only have a 10 solution how much 10 solution and water should be mixed

HESI A2

HESI A2 Math Portion

1. 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 =

2. Sarah had 1 quart of milk. How many ounces of milk is that?

A. 16 ounces
B. 24 ounces
C. 32 ounces
D. 48 ounces

Correct answer: C

Rationale: The correct answer is 32 ounces. One quart is equivalent to 32 ounces. To convert quarts to ounces, you need to know that 1 quart equals 32 ounces. Therefore, 1 quart of milk is equal to 32 ounces. Choices A, B, and D are incorrect as they do not accurately convert 1 quart to ounces.

3. Which of these percentages equals 1.25?

A. 1250%
B. 25%
C. 50%
D. 125%

Correct answer: D

Rationale: To convert 1.25 to a percentage, multiply by 100. Therefore, 1.25 equals 125%. The correct answer is D because 125% is the percentage that represents 1.25. Choices A, B, and C are incorrect. A (1250%) is 10 times greater than the correct answer, B (25%) is 100 times smaller, and C (50%) is 2 times smaller than the correct percentage equivalent of 1.25.

4. What is 20% of 2?

A. 0.4
B. 0.2
C. 0.3
D. 0.1

Correct answer: A

Rationale: To find 20% of a number, you multiply the number by 0.20. In this case, 0.20 * 2 = 0.4. Therefore, 0.4 is 20% of 2. Choice A (0.4) is correct. Choice B (0.2) is incorrect because it represents 10% of 2, not 20%. Choice C (0.3) is incorrect as it is not the result of calculating 20% of 2. Choice D (0.1) is incorrect as it represents 5% of 2, not 20%.

5. What is the result of adding 1/2 + 4/5?

A. 1 3/10
B. 1/2/2024
C. 1 2/5
D. 1 1/5

Correct answer: A

Rationale: To add fractions, you need a common denominator. In this case, the common denominator is 10. So, 1/2 + 4/5 = 5/10 + 8/10 = 13/10 = 1 3/10. Therefore, the correct answer is A: 1 3/10. Choice B, 1/2/2024, is incorrect as it does not represent the sum of the fractions given. Choice C, 1 2/5, is incorrect as it does not match the sum calculated. Choice D, 1 1/5, is incorrect as it does not reflect the correct sum of the fractions provided.