University X requires some of its nursing students to take an exam before being admitted into the nursing program. In this year's class, half of the nursing students were required to take the exam, and three-fifths of those who took the exam passed. If this year's class has 200 students, how many students passed the exam?

Correct Answer: C

Rationale: If the incoming class has 200 students, then half of those students were required to take the exam. (200)(1/2) = 100. So 100 students took the exam, but only three-fifths of that 100 passed the exam. (100)(3/5) = 60. Therefore, 60 students passed the exam. The correct answer is 60. Choice A is incorrect as it miscalculates the number of students who passed the exam. Choice B is incorrect as it does not consider the passing rate of the exam. Choice D is incorrect as it is much lower than the correct answer.

Correct Answer: D

Rationale: The surface area of a cylinder can be calculated using the formula: S = 2πr² + 2πrh, where r is the radius and h is the height. Substituting the values for radius (12) and height (8) into the formula: S = 2π(12)² + 2π(12)(8). S = 2π(144) + 2π(96). S = 288π + 192π. S = 480π ≈ 1507.964. Therefore, the surface area of the cylinder is approximately 1507.2 square centimeters. Choice A, 602.9 cm², is incorrect as it is significantly lower than the correct value. Choice B, 904.3 cm², is also incorrect as it does not match the calculated surface area. Choice C, 1,408.7 cm², is incorrect as it does not align with the calculated value of the surface area.

Correct Answer: A

Rationale: A proportional relationship is one in which two quantities vary directly with each other. In choice A, the amount deposited per month is directly proportional to the initial deposit. The relationship can be represented as y = 125x + 150, where x is the number of months and y is the total amount in the account. Choices B and C involve additional fixed amounts or variable costs that do not maintain a constant ratio, making them non-proportional relationships. Choice D refers to a constant speed of driving, which is not a proportional relationship as it does not involve varying quantities that change in direct proportion.

Correct Answer: D

Rationale: The mean number of vacuum cleaners sold per month is 31.7, the mode is 29, the median is 31, and the range is 29. The mode being equal to the range is the correct statement. Option A is incorrect because the mean (31.7) is greater than the median (31). Option B is incorrect as the mode (29) is not greater than the median (31). Option C is incorrect since the mode (29) is not less than the mean, median, or range.

Correct Answer: D

Rationale: To solve the equation 3(x - 1) = 2(3x - 9), first distribute and simplify both sides to get 3x - 3 = 6x - 18. Next, subtract 3x from both sides to get -3 = 3x - 18. Then, add 18 to both sides to obtain 15 = 3x. Finally, divide by 3 to find x = 5. Therefore, the correct answer is x = 5. Choices A, B, and C are incorrect because they do not represent the correct solution to the given equation after proper algebraic manipulation.