Jeremy put a heavy chalk mark on the tire of his bicycle. His bike tire is 27 inches in diameter. When he rolled the bike, the chalk left marks on the sidewalk. Which expression can be used to best determine the distance, in inches, the bike rolled from the first mark to the fourth mark?

Correct Answer: A

Rationale: The distance traveled by the bike in one complete roll of the tire is equal to the circumference, which can be calculated using the formula C = πd, where d is the diameter. Given that the diameter of the bike tire is 27 inches, the circumference is obtained by multiplying the diameter by π. As the tire rolls from the first mark to the fourth mark, it completes three full rotations (one complete roll plus two more). Therefore, the total distance rolled is 3 times the circumference, which results in 3(27π). Choice A is correct. Choice B is incorrect as it incorrectly multiplies the diameter by 4π instead of multiplying the circumference by 4. Choices C and D are incorrect as they involve dividing the diameter by a number, which is not applicable in this context.

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.

Correct Answer: A

Rationale: To find out the number of months needed to secure 24 new clients, you can set up a proportion: 3 clients / 8 months = 24 clients / x months. Cross multiplying gives you 3x = 24 * 8. Solving for x: 3x = 192, x = 192 / 3, x = 64. Therefore, Robert will secure 24 new clients after 64 months. Choice A is correct. Choice B (58), Choice C (52), and Choice D (66) are incorrect as they do not align with the correct calculation based on the given proportion.