a doctor orders 1 gram of a medication to be administered intravenously the available vial contains 200 milligrams per milliliter how many milliliters

HESI A2

HESI A2 Math Practice

1. A doctor orders 1 gram of a medication to be administered intravenously. The available vial contains 200 milligrams per milliliter. How many milliliters of the solution should be drawn up?

A. 4 milliliters
B. 5 milliliters
C. 10 milliliters
D. 20 milliliters

Correct answer: B

Rationale: 1 gram is equivalent to 1000 milligrams. The concentration of the medication is 200 milligrams per milliliter. To calculate the volume needed, divide the total amount of medication by the concentration: 1000 mg / 200 mg/mL = 5 mL. Therefore, 5 milliliters of the solution should be drawn up to administer 1 gram of the medication intravenously. Choice A (4 milliliters), Choice C (10 milliliters), and Choice D (20 milliliters) are incorrect because they do not accurately calculate the volume of the solution needed based on the concentration of the medication.

2. Convert to metric: 7 grams = x milligrams

A. 700 mg
B. 0.7 mg
C. 7,000 mg
D. 0.07

Correct answer: C

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 is equal to 7,000 milligrams. Choice A (700 mg) is incorrect because it represents grams to milligrams incorrectly. Choice B (0.7 mg) is incorrect as it converts grams to milligrams erroneously by decimal placement. Choice D (0.07) is incorrect as it converts grams to milligrams inaccurately by misplacing the decimal point.

3. Add 7/8 + 9/10 + 6/5. Express the result as a mixed number.

A. 3 & 39/40
B. 3 & 22/23
C. 22/23
D. 2 & 39/40

Correct answer: A

Rationale: To add fractions, find a common denominator, which in this case is 40. Convert each fraction to have the common denominator: 7/8 = 35/40, 9/10 = 36/40, and 6/5 = 48/40. Add these fractions to get 119/40. Simplify this improper fraction to a mixed number, which is 3 & 39/40. Choice B and C are incorrect as they do not represent the sum of the fractions. Choice D is incorrect; the whole number part should be 3, not 2.

4. What is the result of adding 7/8 + 9/10 + 6/5?

A. 3 & 39/40
B. 3 & 22/23
C. 22/23
D. 30

Correct answer: A

Rationale: To add fractions, you need to find a common denominator. The common denominator for 8, 10, and 5 is 40. Then, convert each fraction: 7/8 = 35/40, 9/10 = 36/40, and 6/5 = 24/40. Now, add the fractions: 35/40 + 36/40 + 24/40 = 95/40, which simplifies to 2 15/40 or 2 3/8. Therefore, 7/8 + 9/10 + 6/5 = 3 & 39/40. Choice B is incorrect because it does not represent the correct addition of the fractions. Choice C is incorrect as it does not account for the whole number part. Choice D is incorrect as it is not the sum of the fractions and whole numbers.

5. Joe makes $20 an hour and Tim makes $30 an hour. How many more hours than Tim must Joe work to earn the same amount that Tim makes in 4 hours?

A. 1 hour
B. 2 hours
C. 3 hours
D. 4 hours

Correct answer: B

Rationale: To earn the same amount that Tim makes in 4 hours, Tim earns $30 per hour, totaling $120 in 4 hours. Joe earns $20 per hour, so to match Tim's earnings in 4 hours, Joe must work 2 hours more than Tim. Therefore, Joe needs to work 2 hours more than Tim to earn the same amount that Tim makes in 4 hours. Choices A, C, and D are incorrect as they do not accurately reflect the additional hours Joe needs to work compared to Tim to earn the same amount in 4 hours.