a dice is rolled what is the probability of getting an even number

HESI A2

HESI A2 Math Practice

1. If a dice is rolled, what is the probability of getting an even number?

A. 16%
B. 33%
C. 66%
D. 50%

Correct answer: D

Rationale: When rolling a standard six-sided die, there are three even numbers (2, 4, 6) out of a total of six possible outcomes (1, 2, 3, 4, 5, 6). The probability of rolling an even number can be calculated as the number of favorable outcomes (3) divided by the total number of outcomes (6), which equals 3/6 = 50%. Therefore, the correct answer is D. Choice A (16%) is incorrect because it does not represent the probability of rolling an even number. Choice B (33%) is incorrect as it does not reflect the correct probability. Choice C (66%) is incorrect as well since it overestimates the probability.

2. 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.

3. Find the value of x if x:15=120:225.

A. x=8
B. x=10
C. x=6
D. x=12

Correct answer: A

Rationale: To solve x:15=120:225, set it up as a proportion: x/15 = 120/225. Simplify the right-hand side: 120/225 = 8/15. Now, solve for x by cross-multiplying: x = 8. Therefore, the correct answer is A. Choices B, C, and D are incorrect as they do not align with the correct calculations.

4. Change the following fraction into a ratio: 22/91

A. 22:91
B. 1/3
C. 22/91
D. Not here

Correct answer: A

Rationale: To convert a fraction into a ratio, you express it as a ratio of two numbers separated by a colon. Therefore, 22/91 as a ratio is 22:91. Choice B (1/3) is a different fraction not equivalent to 22/91. Choice C (22/91) is the original fraction and not the ratio form. Choice D is irrelevant to the question.

5. A patient needs to increase his calcium intake. If each tablet contains 500 mg of calcium and the patient needs to take 1,500 mg per day, how many tablets should the patient take?

A. 3 tablets
B. 4 tablets
C. 2 tablets
D. 5 tablets

Correct answer: A

Rationale: To calculate the number of tablets needed, divide the total daily calcium intake required (1,500 mg) by the amount of calcium in each tablet (500 mg). 1,500 mg ÷ 500 mg = 3 tablets. Therefore, the patient should take 3 tablets to meet the 1,500 mg daily intake. Choice B, 4 tablets, is incorrect because it would exceed the required 1,500 mg. Choice C, 2 tablets, is insufficient to meet the daily intake. Choice D, 5 tablets, is also incorrect as it would exceed the required amount.