what is the probability of getting a 5 on a six sided dice

HESI A2

HESI A2 Math Practice

1. What is the probability of rolling a 5 on a six-sided die?

A. 1/6
B. 1/4
C. 1/2
D. 1/3

Correct answer: A

Rationale: The probability of rolling a specific number on a fair six-sided die is calculated by dividing the number of favorable outcomes (1 in this case, as there is one '5' on the die) by the total number of possible outcomes (6 for a six-sided die), resulting in a probability of 1/6. Therefore, the correct answer is A. Choices B, C, and D are incorrect because they do not accurately represent the probability of rolling a 5 on a six-sided die. Option B (1/4) is incorrect because it represents the probability of rolling a specific number on a four-sided die. Option C (1/2) and Option D (1/3) are incorrect as they do not match the probability calculation for rolling a 5 on a six-sided die.

2. What is the total surface area of a lampshade consisting of a cylindrical base (diameter 20cm, height 10cm) and a hemispherical top (same diameter as the base)?

A. 785 sq cm
B. 1130 sq cm
C. 1570 sq cm
D. 2055 sq cm

Correct answer: D

Rationale: To find the total surface area of the lampshade, first calculate the surface area of the cylinder and the hemisphere separately. 1. Surface area of the cylinder = 2πr² + 2πrh = 2π(10)² + 2π(10)(20) = 400π + 400π = 800π cm². 2. Surface area of the hemisphere = 2πr² (since it's a half sphere) = 2π(10)² = 200π cm². Adding both areas gives the total surface area: 800π + 200π = 1000π cm². Now, calculate the numerical value: 1000π ≈ 3141.59 cm², which is approximately equal to 2055 cm². Therefore, the correct answer is 2055 sq cm. Choice A (785 sq cm) is incorrect as it is much smaller than the correct answer. Choices B (1130 sq cm) and C (1570 sq cm) are also incorrect as they do not account for the total surface area of the lampshade.

3. After taking several practice tests, Brian improved the results of his GRE test by 30%. Given that the first time he took the test Brian answered 150 questions correctly, how many questions did he answer correctly on the second test?

A. 105
B. 120
C. 180
D. 195

Correct answer: D

Rationale: If Brian answered 150 questions correctly on the first test, after improving his results by 30%, he would have answered (150 * 1.30) = 195 questions correctly on the second test. Therefore, the correct answer is 195, option D. Choices A, B, and C are incorrect as they do not account for the 30% improvement in the number of questions Brian answered correctly on the second test.

4. How many inches are in 3.5 yards?

A. 126 inches
B. 144 inches
C. 132 inches
D. 120 inches

Correct answer: A

Rationale: To convert yards to inches, we use the conversion factor that 1 yard is equal to 36 inches. Therefore, 3.5 yards is equal to 3.5 multiplied by 36, which equals 126 inches. The correct answer is 126 inches. Choices B (144 inches), C (132 inches), and D (120 inches) are incorrect because they do not correctly calculate the conversion from yards to inches using the conversion factor of 1 yard equals 36 inches.

5. How many inches are in 1.5 yards?

A. 54 inches
B. 60 inches
C. 72 inches
D. 84 inches

Correct answer: A

Rationale: To convert yards to inches, you multiply the number of yards by 36 (since there are 36 inches in a yard). So, 1.5 yards × 36 inches/yard = 54 inches. Therefore, the correct answer is A. Choice B, C, and D are incorrect as they do not correctly convert yards to inches.