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. What number is 98 175% of?

A. 48
B. 52
C. 54
D. 56

Correct answer: D

Rationale: To find the number that 98 is 175% of, we can set up the equation: x = 1.75 * x. By solving this equation, we get x = 56. Therefore, 98 is 175% of 56. Choice D, 56, is the correct answer as it represents the number that satisfies the given condition. Choices A, B, and C are incorrect as they do not result in 98 when multiplied by 1.75.

3. A person consumed 75 grams of protein. This is 30% of the recommended daily intake (RDI) for protein. How many grams of protein does the person need to consume to meet the full RDI?

A. 250 grams
B. 225 grams
C. 260 grams
D. 300 grams

Correct answer: A

Rationale: To find the full RDI, divide the amount of protein consumed (75 grams) by 30% (or 0.30): 75 ÷ 0.30 = 250 grams. Therefore, the person needs 250 grams of protein to meet the full RDI. Choice A is correct because it accurately calculates the amount needed to reach the full RDI. Choices B, C, and D are incorrect as they do not correctly calculate the total amount of protein needed based on the given information.

4. What is the ratio of women to the total number of students in the class?

A. 4:7
B. 16:28
C. 3:5
D. 2:3

Correct answer: A

Rationale: To find the ratio of women to the total number of students, you need to simplify the ratio of 16:28. By dividing both numbers by the greatest common factor, which is 4, you get 4:7. Therefore, the correct ratio of women to the total number of students is 4:7. Choice A is correct. Choices C and D are incorrect because they do not represent a valid ratio. Choice B is the original ratio given in the question, which should be simplified to 4:7 as explained in the rationale.

5. What is the product of 375 and 2.3?

A. 862.5
B. 750
C. 225.75
D. 1125

Correct answer: A

Rationale: To find the product of 375 and 2.3, multiply them: 375 × 2.3 = 862.5. When multiplying by 2.3, it is important to shift the decimal point appropriately after performing the calculation. Choice A, 862.5, is the correct answer. Choice B, 750, is incorrect because it is the result of multiplying 375 by 2. Choice C, 225.75, is incorrect as it appears to be the result of multiplying the numbers in the wrong order. Choice D, 1125, is incorrect as it seems to be the result of multiplying 375 by 3 instead of 2.3.