A train travels at 70 mph for 6 hours. How far did it travel?

Correct Answer: D

Rationale: To find the distance traveled, multiply the speed of 70 mph by the time of 6 hours: 70 mph 6 hours = 420 miles. Therefore, the correct answer is 420 miles. Choices A, B, and C are incorrect as they do not result from the correct calculation.

Correct Answer: B

Rationale: The correct answer is B: Decimal. The decimal system, also known as the base-10 system, is the standard system for denoting integer and non-integer numbers in the United States and many other countries. In the decimal system, numbers are represented using 10 digits (0-9). Choices A, C, and D are incorrect. Tertiary, Napoleonic, and Binary number systems are not commonly used for general number representation in the United States.

Correct Answer: C

Rationale: Rationale: The correct answer is obtained by applying the formula for the circumference of a circle, which is \(C = \pi \times d\), where \(d\) is the diameter of the circle. By substituting the given diameter of 40cm into the formula and performing the calculation, we find that the circumference of the pizza is 125.6cm.

Correct Answer: A

Rationale: When dividing fractions, you multiply by the reciprocal of the divisor. To divide 5 3/4 by 1/2, you multiply 5 3/4 by 2/1 (reciprocal of 1/2) to get 23/4 * 2/1 = 46/4 = 11 1/2. Therefore, the correct answer is A. Choice B (2 & 3/8) is incorrect as it does not result from dividing 5 3/4 by 1/2. Choice C (3 & 1/8) is incorrect as well. Choice D (18) is not the correct result of the division performed.

Correct Answer: A

Rationale: To add fractions with different denominators, find a common denominator. In this case, the common denominator of 4 and 8 is 8. Convert 1/4 to 2/8, then add it to 3/8. The sum is 5/8. Choice B (7/12) is incorrect as it is the result of adding 1/3 + 1/4. Choice C (2/3) is incorrect as it is the result of adding 3/8 + 1/4. Choice D (1/2) is incorrect as it is the result of adding 1/4 + 1/4.