Correct Answer: D

Rationale: The runner left at 7:45 and returned at 10:00, which means he ran for 2 hours and 15 minutes (10:00 - 7:45). At an average speed of 6 mph, in 2.25 hours, he would have covered 6 mph * 2.25 hours = 13.5 miles. Therefore, the correct answer is 13.5 miles. Choices A, B, and C are incorrect because they incorrectly calculate the distance based on the time and speed provided in the question.

Correct Answer: D

Rationale: To determine the highest number among 0.077, 0.777, 0.08, and 0.87, we compare the numbers. 0.87 is greater than 0.777, 0.08, and 0.077, making it the highest number. Choice A (0.077), Choice B (0.777), and Choice C (0.08) are lower numbers compared to 0.87, so they are incorrect.

Correct Answer: D

Rationale: The runner left at 7:45 and returned at 10:00, which means he ran for 2 hours and 15 minutes (10:00 - 7:45). At an average speed of 6 mph, in 2.25 hours, he would have covered 6 mph * 2.25 hours = 13.5 miles. Therefore, the correct answer is 13.5 miles. Choices A, B, and C are incorrect because they incorrectly calculate the distance based on the time and speed provided in the question.

Correct Answer: B

Rationale: The correct answer is B: $50. To calculate the interest earned on an investment with a 5% interest rate on a principal of $1,000, you simply multiply the principal amount by the interest rate. 5% of $1,000 is $50. Therefore, the investment will earn $50 in interest in 1 year. Choice A, $40, is incorrect because it represents 4% interest instead of 5%. Choice C, $60, is incorrect because it overestimates the interest earned. Choice D, $55, is incorrect as it does not accurately reflect the 5% interest on the principal amount.

Correct Answer: B

Rationale: If Janice sells 690 vacuum cleaners per year, Randy sells 8 times that amount, which is 690 x 8 = 5,520 vacuum cleaners per year. To find out how many Randy sells each month, you divide 5,520 by 12 (months), which equals 460 vacuum cleaners per month. Therefore, Randy sells 5,520 vacuum cleaners per year divided by 12 months, which equals 460 vacuum cleaners per month. Choices A, C, and D are incorrect as they do not reflect the correct calculation based on the information provided.