Correct Answer: B

Rationale: To find the total cost, first calculate the cost of pens and staplers separately. 240 pens require 40 packs (240 pens · 6 pens per pack = 40 packs). Each pack of pens costs $2.35, so 40 packs cost $94 (40 packs $2.35 per pack = $94). For the staplers, 6 staplers require 3 packs (6 staplers · 2 staplers per pack = 3 packs). Each pack of staplers costs $12.95, so 3 packs cost $38.85 (3 packs $12.95 per pack = $38.85). Adding the cost of pens and staplers together gives a total of $132.85, which rounds to $132.00. Therefore, the correct answer is $132.00. Choice A is incorrect as it does not consider the individual prices of pens and staplers. Choice C is incorrect as it overestimates the total cost by combining the costs incorrectly. Choice D is incorrect as it underestimates the total cost by not considering both pens and staplers.

Correct Answer: A

Rationale: To find out how many gallons are in the tank when it is 3/4 full, you need to calculate 3/4 of 16 gallons. 3/4 of 16 is (3/4) x 16 = 12 gallons. Therefore, the car's gas tank contains 12 gallons when it is 3/4 full. Choice B (8 gallons) is incorrect because that would be 1/2 of the tank's capacity, not 3/4. Choice C (14 gallons) is incorrect as it exceeds the full capacity of the tank. Choice D (10 gallons) is incorrect as it is less than 3/4 of the tank's capacity.

Correct Answer: A

Rationale: If 3 bags of chips cost $4.50, then the cost per bag is $4.50/3 = $1.50. To buy five bags, John would need to pay 5 bags * $1.50 = $7.50. Therefore, it will cost John $7.50 to buy five bags of chips. The other choices are incorrect because they do not accurately calculate the total cost based on the given information.

Correct Answer: B

Rationale: To solve the proportion 0.1:10=x:400, first, simplify the left side to 1:100. Then, set up the proportion as 1:100=x:400. Cross multiply to get x = 4. Therefore, the correct answer is B. Choice A (5) is incorrect because it does not match the calculated value of x. Choice C (50) is incorrect as it is not the result of solving the proportion provided. Choice D (25) is incorrect as it does not align with the correct calculation of x.

Correct Answer: C

Rationale: Rationale: To find the least common multiple (LCM) of 14 and 21, we need to determine the smallest number that is a multiple of both 14 and 21. First, list the multiples of 14: 14, 28, 42, 56, 70, 84, ... Next, list the multiples of 21: 21, 42, 63, 84, ... The smallest number that appears in both lists is 42. Therefore, the LCM of 14 and 21 is 42.