Q: James has an old printer that crumples every seventh page and blurs the ink on every third page. If he prints 42 pages, how many are neither crumpled or blurred?
A: First find the total number of pages that are crumpled: 42 pages / 7 = 6 pages. Then find the total number of pages that are blurred: 42 pages / 3 = 14 pages. Then find the number of pages that are both blurred and crumpled by finding how many numbers are less or equal to 42 and divisible by both 3 and 7: there are two, 21 and 42. Then subtract the number of crumpled and blurred pages from the total number of pages, and add the number of pages that were double - counted because they were both blurred and crumpled: 42 pages - 6 pages - 14 pages + 2 pages = 24 pages. The answer is 24.

Q: A single kabob stick has 4 cubes of beef. A slab of beef that costs $25 can be cut into 80 cubes. How much must Simon spend to make 40 kabob sticks?
A: One slab of beef can make 80 / 4 = 20 kabob sticks. To make 40 kabob sticks, Simon needs 40 / 20 = 2 slabs of beef. Simon must spend $25 x 2 = $50. The answer is 50.

Q: Bo is learning words for the GRE. He got 800 flashcards. He knew 20% of the words on them. He has 40 days to learn the rest. How many words does he need to learn a day?
A:
He knows 800 * .2 = 160 words. So he needs to learn 800 - 160 = 640 words. That means he needs to learn 640 / 40 = 16 words per day. The answer is 16.