Come up with a question and reasoning that would justify this answer: 9
Question and rationale: The question is: Joey has 30 pages to read for history class tonight. He decided that he would take a break when he finished reading 70% of the pages assigned. How many pages must he read after he takes a break?
Step-by-step reasoning process: Joey will take a break after 30 * 0.7 = 21 pages. Joey will have to read 30 - 21 = 9 pages more.

Come up with a question and reasoning that would justify this answer: 250
Question and rationale: The question is: Cary walks 3 miles round-trip to the grocery store, where he buys and eats a candy bar with 200 calories. If Cary burns 150 calories per mile walked, what's Cary's net calorie deficit (expressed as a positive number)?
Step-by-step reasoning process: First, find how many calories the walk burned by multiplying the calories burned per mile by the number of miles Cary walked: 3 miles * 150 calories / mile = 450 calories. Then subtract the calories Corey ate to find the net calories Cary burned: 450 calories - 200 calories = 250 calories.

Come up with a question and reasoning that would justify this answer: 21
Question and rationale: The question is: Candice read 3 times as many books as Amanda in their school's Book Tournament. Kara read half the number of books that Amanda read, and Patricia read 7 times the number of books that Kara read. If Candice read 18 books, how many books did Patricia read?
Step-by-step reasoning process: Amanda read 18 / 3 = 6 books. Kara read 6 / 2 = 3 books. Patricia read 7 x 3 = 21 books.

Come up with a question and reasoning that would justify this answer: 75
Question and rationale:
The question is: Kyle bought 2 glass bottles that can hold 15 origami stars each. He then bought another 3 identical glass bottles. How many stars must Kyle make to fill all the glass bottles he bought?
Step-by-step reasoning process: Kyle has 2 + 3 = 5 glass bottles. He needs to make 15 x 5 = 75 origami stars.