HESI A2 Math Portion

Correct Answer: B

Rationale: Rebecca can paint 12 pickets in 1 hour, which means she can paint 12 * 2 = 24 pickets in an hour. Since the fence is 72 feet long with 2 pickets per foot, she needs to paint a total of 72 * 2 = 144 pickets. If she paints 24 pickets per hour, it will take her 144 / 24 = 6 hours to paint the entire fence. Choice A (2.4 hours) is incorrect because it does not consider the total number of pickets on the fence. Choice C (12 hours) is incorrect as it overestimates the time needed based on her painting rate. Choice D (16.4 hours) is incorrect as it miscalculates the time required to paint the entire fence.

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.

Correct Answer: D

Rationale: When you multiply 2 by 5, the result is 10, not 13. Therefore, the correct answer is 10, which is option D. Choices A, B, and C are incorrect because they do not represent the correct product of multiplying 2 by 5.

Correct Answer: A

Rationale: Military time uses a 24-hour clock format where the hours range from 00 to 23. In this format, 6:30 A.M. is expressed as 0630. Choice B (6030) and Choice C (1503) are incorrect as they do not follow the 24-hour clock format. Choice D (1530) represents 3:30 P.M., not 6:30 A.M.

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.