Math HESI A2 Practice Test

Correct Answer: A

Rationale: To divide 5 3/4 by 1/2, we convert 5 3/4 to an improper fraction as 23/4. Then, we divide 23/4 by 1/2, which is equivalent to multiplying by the reciprocal of 1/2, which is 2. Therefore, 23/4 * 2 = 46/4 = 11 1/2. The correct answer is A. Other choices are incorrect as they do not result from the correct calculation process.

Correct Answer: A

Rationale: To convert grams to milligrams, you multiply by 1000 since there are 1000 milligrams in a gram. So, 7 grams x 1000 = 7000 mg. Therefore, the correct answer is A: 7000 mg. Option B (7 mg) is incorrect because it represents the original unit (grams). Option C (700 mg) is incorrect as it is a partial conversion error. Option D (70 mg) is incorrect as it is a multiple of 10 error.

Correct Answer: C

Rationale: To find the total words typed in 20 minutes, multiply words per minute by minutes: 45 words/minute x 20 minutes = 900 words. Thus, the correct answer is C (900 words). A is incorrect as it miscalculates the total. B is incorrect as it underestimates the total. D is incorrect as it duplicates option A.

Correct Answer: A

Rationale: To add 3 1/8 and 1 1/4, first convert both to improper fractions: 3 1/8 = 25/8 and 1 1/4 = 5/4. Then, add the fractions: 25/8 + 5/4 = 50/8 + 10/8 = 60/8 = 7 1/2. Convert 7 1/2 back to a mixed number: 7 1/2 = 6 2/8 = 6 1/4 = 4 3/8, which is the correct answer (A). Choice B (4 1/2) is incorrect as it doesn't match the calculated sum. Choice C (4 3/4) is incorrect as it is not the simplified form of the sum. Choice D (5 1/4) is incorrect as it is higher than the calculated sum.

Correct Answer: A

Rationale: To subtract mixed numbers, first convert them to improper fractions. 15 3/4 = (4*15+3)/4 = 63/4, and 8 2/5 = (5*8+2)/5 = 42/5. Then, find a common denominator, which is 20 in this case. Subtract the fractions: 63/4 - 42/5 = (63*5 - 42*4)/20 = (315 - 168)/20 = 147/20. Finally, convert the result back to a mixed number: 147/20 = 7 7/20. Therefore, the correct answer is A: 7 7/20. Choices B, C, and D are incorrect because they do not correctly represent the result of the subtraction calculation.