Correct Answer: B

Rationale: The total cost (T) consists of the initial charge of $40 plus the additional charges based on the number of tablecloths. The correct expression for T is T = 5c + 3.5r + 40. This accounts for the $5 per circular tablecloth (5c), $3.50 per rectangular tablecloth (3.5r), and the initial $40 charge. Choice A is incorrect as it subtracts the initial charge instead of adding it. Choice C is also incorrect as it subtracts the initial charge and has the coefficients in the wrong positions. Choice D adds the initial charge at the end instead of at the beginning, making it incorrect. Therefore, choice B is the correct representation of the total cost to rent tablecloths.

Correct Answer: A

Rationale: To solve the equation 3(x-2)=12, first distribute the 3: 3x - 6 = 12. Next, isolate x by adding 6 to both sides: 3x = 18. Finally, divide by 3 to find x: x = 6. Therefore, the correct answer is A (6). Choice B (-2) is incorrect as it does not satisfy the equation. Choice C (-4) is also incorrect as it does not satisfy the equation. Choice D (2) is incorrect as it does not satisfy the equation either.

Correct Answer: A

Rationale: To convert pounds to kg, you need to divide by 2.2, not multiply. Similarly, to convert kg to pounds, you should multiply by 2.2. Therefore, choice A is correct. Choices B, C, and D are incorrect because they provide incorrect conversion factors for pounds and kg, leading to inaccurate results.

Correct Answer: C

Rationale: The baby's measured weight is the dependent variable as it depends on the time intervals.

Correct Answer: A

Rationale: After the $400 down payment, the remaining balance is $1,170. With monthly payments of $100, it will take 12 months to pay off the remaining balance. Therefore, the correct answer is 12 months. Choice B (16) is incorrect as it exceeds the required timeframe. Choice C (15) is incorrect as it is close but still one month over the correct timeframe. Choice D (11) is incorrect as it underestimates the time needed to pay off the remaining balance.