Correct Answer: C

Rationale: To find the solution, first solve the expression inside the parentheses: 25 - 21 = 4. Then, square the result from the parentheses: 4² = 16. Next, perform the multiplication: 4 x 7 = 28. Finally, add the results: 28 + 16 = 44. Therefore, the correct answer is 44. Choice A (512), Choice B (36), and Choice D (22) are incorrect as they do not follow the correct order of operations for solving the given mathematical expression.

Correct Answer: C

Rationale: To determine the number of questions the student solved correctly, we need to calculate 85% of the total number of questions. This can be done by multiplying the total number of questions by 85%, which is 20 questions x 85% = 20 x 0.85 = 17 questions. Therefore, the student solved 17 questions correctly. Choice A, 15, is incorrect as it does not reflect the correct percentage of questions solved. Choice B, 16, and Choice D, 18, are also incorrect as they do not match the calculation based on the given percentage.

Correct Answer: B

Rationale: The total number of faculty members is 15 teachers + 20 teaching assistants = 35. The ratio of faculty to students is then 35:200, which simplifies to 7:40. Further simplifying by dividing both numbers by 5 gives the ratio 4:20, which can be simplified to 4:17. Therefore, the correct ratio is 4:17. Choices A, C, and D are incorrect ratios and do not match the calculated ratio of faculty members to students in this scenario.

Correct Answer: B

Rationale: To calculate the percentage increase, use the formula: Percentage Increase = ((New Value - Original Value) / Original Value) x 100 Substitute the values: ((60 - 40) / 40) x 100 = (20 / 40) x 100 = 0.5 x 100 = 50% Therefore, the correct answer is 50%. Choice A (26%) is incorrect as the percentage increase is not 26%. Choice C (35%) is incorrect as the percentage increase is not 35%. Choice D (12%) is incorrect as the percentage increase is not 12%.

Correct Answer: C

Rationale: To find the value of b in the equation 5b - 4 = 2b + 17, you need to first simplify the equation. By subtracting 2b from both sides of the equation and adding 4 to both sides, you get 3b = 21. Then, dividing both sides of the equation by 3 gives you b = 7. Therefore, the value of b is 7, which corresponds to option C. Choice A (13) is incorrect as it does not match the correct calculation. Choice B (24) is incorrect as it is not the result of the correct algebraic manipulation. Choice D (21) is incorrect as it is not the value of b obtained after solving the equation step by step.