Correct Answer: A

Rationale: To solve for x, use cross-multiplication: 6x = 10 x 24 6x = 240 Now, divide both sides by 6 to find x: x = 240 / 6 = 40 Therefore, the correct answer is A. 40. Choice B, 25, is incorrect because it does not satisfy the proportion. Choice C, 240, is incorrect because it represents the value that is given in the proportion and not the value of x. Choice D, 4, is incorrect as it does not align with the correct calculation for x.

Correct Answer: A

Rationale: To find the amount earned for 6 hours of work, calculate the hourly rate by dividing the total earnings ($120) by the total hours worked (10 hours): $120 · 10 = $12 per hour. Then, multiply the hourly rate by the number of hours worked (6): $12 6 = $72. Therefore, the student earned $72 for working 6 hours. Choice B ($90) is incorrect because it miscalculates the hourly rate. Choice C ($80) is incorrect as it does not consider the correct hourly rate. Choice D ($50) is incorrect as it calculates the earnings based on the wrong hourly rate.

Correct Answer: C

Rationale: 12 - 7 & 4\5 equals 4 & 1\5.

Correct Answer: A

Rationale: To find the total number of staff members, sum up the different roles: 25 (nurses) + 75 (assistants) + 5 (phlebotomists) + 6 (office staff) + 45 (physicians) = 156 total staff. Then, calculate 68% of the total staff: 156 0.68 = 106.08, which is approximately 106 people. Therefore, 106 people were working that day. Choice A is correct. Choices B, C, and D are incorrect as they do not reflect the accurate calculation based on the given information.

Correct Answer: A

Rationale: When adding fractions with the same denominator, you simply add the numerators while keeping the denominator the same. In this case, 7/21 + 10/21 = 17/21. Therefore, the correct answer is A. Choice B (15/21) is incorrect because it adds the numerators incorrectly. Choice C (9/21) is incorrect as it does not reflect the sum of the fractions provided. Choice D (10/21) is also incorrect as it does not represent the correct sum of the two fractions.