[Question]: Mary and Ann are going sledding. Mary slides down a hill that's 630 feet long at a speed of 90 feet/minute. Ann slides down a hill that's 800 feet long at a rate of 40 feet/minute. How much longer does Ann's trip take than Mary?
[Answer]: First find the total time Mary's trip takes: 630 feet / 90 feet / minute = 7 minutes. Then find the total time Ann's trip takes: 800 feet / 40 feet / minute = 20 minutes. Then subtract Mary's time from Ann's time to find the difference: 20 minutes - 7 minutes = 13 minutes.
So the answer is 13.

[Question]: If one fourth of the engines are defective, and there are 5 batches of 80 engines each. How many engines are not defective?
[Answer]: There are 80 * 5 = 400 engines in total. 400 / 4 = 100 of the engines are defective. 400 - 100 = 300 of the engines are not defective.
So the answer is 300.

[Question]: Carson needs to mow the lawn and plant some flowers. Carson has to mow 40 lines to cover the whole yard, and it takes him 2 minutes to mow one line. He also needs to plant 8 rows of flowers, each with 7 flowers, and it takes him half a minute to plant each flower. How many minutes will Carson spend gardening?
[Answer]:
First find the total time Carson spends mowing: 40 lines * 2 minutes / line = 80 minutes. Then find the total number of flowers Carson plants: 8 rows * 7 flowers / row = 56 flowers. Then multiply that number by the time taken to plant each flower to find the total time spent planting flowers: .5 minutes / flower * 56 flowers = 28 minutes. Finally, add that time to the time spent mowing to find the total time spent gardening: 28 minutes + 80 minutes = 108 minutes.
So the answer is 108.