A train travels at a constant speed of 60 mph for 2 hours. How many miles did the train travel?

Correct Answer: A

Rationale: To determine the distance traveled by the train, you multiply the speed by the time: 60 mph 2 hours = 120 miles. Therefore, the correct answer is 120 miles. Choice B, 180 miles, is incorrect as it results from multiplying the speed by 3 hours instead of 2. Choice C, 100 miles, is incorrect as it results from multiplying the speed by 1.5 hours. Choice D, 240 miles, is incorrect as it results from multiplying the speed by 4 hours instead of 2.

Correct Answer: C

Rationale: To convert ounces to pounds, divide the number of ounces by 16 since there are 16 ounces in a pound. Therefore, 192 ounces · 16 = 12 pounds. Choice A, 16 pounds, is incorrect because it does not represent the correct conversion from ounces to pounds. Choice B, 10 pounds, is incorrect as it is not the result of dividing 192 ounces by 16. Choice D, 16 pounds, is the same as choice A and is incorrect in the context of this conversion.

Correct Answer: C

Rationale: To convert liters to milliliters, you must remember that 1 liter is equal to 1,000 milliliters. Therefore, to find out how many milliliters are in 4 liters, you multiply 4 by 1,000. This gives you a total of 4,000 milliliters in 4 liters. Choices A, B, and D are incorrect because they do not correctly convert liters to milliliters. A and B incorrectly represent 40 milliliters, which would be the result if you mistakenly multiplied by 10 instead of 1,000. Choice D is even further from the correct answer, as it suggests only 4 milliliters, which is significantly less than the actual conversion of 4 liters to milliliters.

Correct Answer: B

Rationale: To find the sum of fractions with the same denominator, add the numerators. Here, 3/7 + 4/7 + 2/7 = (3 + 4 + 2)/7 = 9/7. Therefore, the correct answer is 9/7. Choice A (7/7) is incorrect as the sum is not 7/7. Choice C (6/7) is incorrect as the sum is not 6/7. Choice D (7/7) is incorrect as the sum is not 7/7.

Correct Answer: A

Rationale: To convert liters to milliliters, remember there are 1,000 milliliters in a liter. So, to find how many milliliters are in 5 liters, you multiply 5 (liters) by 1,000 (milliliters per liter), which equals 5,000 milliliters. Choice A is correct as it converts 5 liters to milliliters accurately. Choice B, 50 milliliters, is incorrect as it mistakenly converts liters to milliliters by a factor of 100 instead of 1,000. Choice C, 500 milliliters, is incorrect as it also wrongly converts liters to milliliters by a factor of 10 instead of 1,000. Choice D, 0.5 milliliters, is incorrect as it inaccurately converts 5 liters to 0.5 milliliters, which is not correct.