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. 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.

3. Subtract 14.5 - 7.25.

A. 7.15
B. 7.25
C. 7.15
D. 7.5

Correct answer: B

Rationale: The correct answer is B. When you subtract 7.25 from 14.5, you get 7.25. The difference between 14.5 and 7.25 is 7.25. Choices A, C, and D are incorrect. Choice A (7.15) is the result of incorrectly subtracting 14.5 - 7.25. Choice C repeats choice A, so it is also wrong. Choice D (7.5) is not the correct result of the subtraction provided in the question.

4. A teacher's aide is preparing a snack for the class. In order to prepare the powdered drink, the aide must convert the directions to metric. The directions say, 'Dilute contents of package in 3 quarts of water.' The aide has a measuring device marked in liters. How many liters of water should be used?

A. 3.0 liters
B. 2.8 liters
C. 2.5 liters
D. 3.5 liters

Correct answer: B

Rationale: 3 quarts is approximately 2.8 liters. To convert quarts to liters, multiply the number of quarts by 0.946353. Therefore, the correct answer is 2.8 liters. Choice A (3.0 liters) is incorrect as it does not accurately convert 3 quarts to liters. Choice C (2.5 liters) is incorrect as it is less than the correct conversion. Choice D (3.5 liters) is incorrect as it is more than the correct conversion.

5. A water fountain has a spherical base with a diameter of 50cm and a cylindrical body with a diameter of 30cm and a height of 80cm. What is the total surface area of the fountain (excluding the water surface)?

A. 3142 sq cm
B. 4712 sq cm
C. 5486 sq cm
D. 7957 sq cm

Correct answer: C

Rationale: To find the total surface area of the fountain, we first calculate the surface area of the sphere and the cylinder separately. For the sphere: - Radius = Diameter / 2 = 50 / 2 = 25 cm - Surface area of a sphere = 4πr² = 4 x π x 25² = 500π cm² For the cylinder: - Radius = Diameter / 2 = 30 / 2 = 15 cm - Surface area of a cylinder = 2πrh + 2πr² = 2 x π x 15 x 80 + 2 x π x 15² = 240π + 450π = 690π cm² Total surface area = Surface area of sphere + Surface area of cylinder = 500π + 690π = 1190π cm² ≈ 5486 sq cm. Therefore, the correct answer is C. Choice A (3142 sq cm) is incorrect as it is much smaller than the correct answer. Choices B and D are also incorrect as they do not reflect the accurate calculation of the total surface area of the fountain.