HESI A2
HESI A2 Math Portion Questions
Question 1 of 5
A bag contains 5 red marbles and 7 blue marbles. If you draw a marble without looking, what is the probability it will be red?
Correct Answer: B
Rationale: The total number of marbles in the bag is 5 (red) + 7 (blue) = 12 marbles. The probability of drawing a red marble is the number of red marbles divided by the total number of marbles: 5/12. Simplifying 5/12 gives 1/3. Therefore, the correct probability of drawing a red marble is 1/3. Choice A (1/4) is incorrect because there are more red marbles than 1/4 of the total marbles. Choice C (1/2) is incorrect as it represents half of the total marbles. Choice D (2/3) is incorrect as it implies there are more red marbles than there actually are.
Question 2 of 5
A child's toy block is a cube with side lengths of 5cm. What is its total surface area?
Correct Answer: D
Rationale: The surface area of a cube is calculated using the formula: 6 * (side length)^2. Substituting the side length of 5cm into the formula, we get: 6 * (5cm)^2 = 6 * 25cm^2 = 150 sq cm. Therefore, the total surface area of the toy block is 150 sq cm. Choices A (25 sq cm), B (50 sq cm), and C (125 sq cm) are incorrect as they do not correctly calculate the total surface area of the cube.
Question 3 of 5
An ancient Egyptian pyramid has a square base with side lengths of 20 meters and a remaining height (after erosion) of 10 meters. Its original height was 30 meters. What was the volume of the pyramid in its original state?
Correct Answer: A
Rationale: To find the volume of a pyramid, you can use the formula: Volume = (1/3) * base area * height. In this case, the base area is the square of side length 20 meters, which is 20 * 20 = 400 square meters. The original height of the pyramid is 30 meters. Therefore, the volume of the pyramid in its original state is (1/3) * 400 * 30 = 12000 cubic meters. Choice A is correct. Choices B, C, and D are incorrect as they do not correctly calculate the volume using the original height and base area of the pyramid.
Question 4 of 5
A patient's oxygen flow rate is set at 4 liters per minute. How many cubic centimeters of oxygen are delivered per minute?
Correct Answer: B
Rationale: 1 liter is equal to 1,000 cubic centimeters. Therefore, when the oxygen flow rate is 4 liters per minute, the calculation is 4 x 1,000 = 4,000 cubic centimeters. Hence, at a flow rate of 4 liters per minute, 4,000 cubic centimeters of oxygen are delivered per minute. Choice A, 400 cubic centimeters, is incorrect because it miscalculates the conversion from liters to cubic centimeters. Choices C and D, 40,000 cubic centimeters and 400,000 cubic centimeters, respectively, are significantly higher than the correct answer due to incorrect conversions or additional errors in calculation.
Question 5 of 5
Relatively prime numbers share no common factors other than 1. Which of the following pairs of numbers are relatively prime?
Correct Answer: B
Rationale: Rationale: - Relatively prime numbers are numbers that share no common factors other than 1. - To determine if two numbers are relatively prime, we need to find the greatest common divisor (GCD) of the two numbers. If the GCD is 1, then the numbers are relatively prime. - Let's calculate the GCD for each pair of numbers: A) GCD(12, 16) = 4, not relatively prime B) GCD(15, 17) = 1, relatively prime C) GCD(20, 24) = 4, not relatively prime D) GCD(28, 36) = 4, not relatively prime Therefore, the pair of numbers 15 and 17 are relatively prime because their greatest common divisor is 1, meaning they share no common factors other than 1.