Harry wants to build a homemade helium balloon with his son, Kevin, so he and Kevin go to the store with $200. They buy a giant sheet to turn into a balloon for $42, a rope for $18, and a propane tank and burner for $14. They plan to use the rest of the money on helium. The helium is $1.50 per ounce. For every ounce they buy, the balloon can fly 113 feet higher. How many feet up can they fly the balloon? Give the rationale and then the answer.
Let's think step by step. They have $126 for helium because 200 - 42 - 18 - 14 = 126. They can buy 84 ounces of helium because 126 / 1.5 = 84. They can fly 9,492 feet up because 84 x 113 = 9,492.. The answer is: 9492.

Miriam spent 30 minutes doing laundry, 15 minutes cleaning the bathroom, a certain amount of time cleaning her room, and 40 minutes doing homework. If she spent a total of two hours on these tasks, how long, in minutes, did she spend cleaning her room? Give the rationale and then the answer.
Let's think step by step. There are 30 + 15 + 40 = 85 minutes accounted for. She spent 2 * 60 = 120 minutes. She spent 120 - 85 = 35 minutes cleaning her room.. The answer is: 35.

Anahi bought a 500 pages book to write some notes on. In the first week, she wrote on 150 pages. In the second week, she wrote on 30% of the remaining pages. While continuing writing, she accidentally spilled coffee on the book and damaged 20 percent of the empty pages she was to write on. Calculate the total number of empty pages available for her to write on now. Give the rationale and then the answer.
Let's think step by step. If she bought a 500 pages book and wrote on 150 pages, the number of empty pages remaining is 500 - 150 = 350 pages. She then wrote on 30% of the remaining empty pages on the second week, a total of 30 / 100 * 350 = 105 pages. The number of remaining empty pages is 350 - 105 = 245 pages. When she spilled coffee on the remaining empty pages, the number of damaged pages was 20 / 100 * 245 = 49. The number of empty pages remaining that she could write on is 245 - 49 = 196 pages.. The answer is: 196.