First find how much soda Danny drank: 1 bottle * .9 = .9 bottles. Then find how much soda Danny gave to his friends: 2 friends * 1 bottle / friend * .7 = 1.4 bottles. Now subtract the soda drunk and given away to find the remaining amount of soda: 3 bottles - .9 bottles - 1.4 bottles = .7 bottles * 100% = 70%.
The answer: 70
Reverse engineering the question: Danny has 3 bottles of soda. He drinks 90% of one bottle and gives 70% of the other two bottles to his friends. How much soda does Danny have left, expressed as a percentage of a bottle?
Reasoning and answer: First figure out how many liters of water are left in the pool when it's 80% full: 2000L * .8 = 1600 L. Now subtract that amount from the pool's total capacity to find how much water can splash out before Jim has to refill it: 2000 L - 1600 L = 400 L. Now multiply that amount by 1000 to convert it to milliliters: 400 L * 1000 ml / L = 400,000 ml. Finally, divide that amount by the amount that splashes out with each jump to find the number of jumps before pool cleaning: 400,000 ml / 400 ml / jump = 1000 jumps.
The answer: 1000
What was the question?
Question: Jim is a maintenance worker at a pool. Every time someone jumps in the pool, they cause 400 ml of water to splash out and evaporate. Jim has to get everyone out of the pool, clean, and refill it when it gets below 80% full. If the pool holds 2000 L of water, how many times can people jump in the pool before Jim has to clean it?
Katy read twice as many books in July as she did in June, so she read 2 * 8 = 16 books in July. She read three fewer books in August than she did in July, so she read 16 - 3 = 13 books in August. So, including June, she read 8 + 16 + 13 = 37 books total.
The answer: 37
Reverse engineering the question: Katy participated in a summer reading program at her local library. She read 8 books in June, twice as many in July and three fewer in August than she did in July. How many books did Katy read during the summer?
Reasoning and answer: Abigail collected 2 * 48 = 96 cookies. There are 48 / 4 = 12 cookies in a quarter of a box. Grayson collected 12 * 3 = 36 cookies. Olivia collected 48 * 3 = 144 cookies. In total they collected 96 + 36 + 144 = 276 cookies.
The answer: 276
What was the question?
Question: Abigail collected 2 boxes of cookies for the bake sale. Grayson collected 3 quarters of a box, and Olivia collected 3 boxes. Assuming that each box contains 48 cookies, how many cookies did they collect in total?
There a total of 8 x 12 = 96 seats on that plane. Only 8 x 3 / 4 = 6 seats are allowed to be seated in each row. So, only 6 x 12 = 72 seats are allowed to be seated on the plane. Therefore, 96 - 72 = 24 seats will not be occupied.
The answer: 24
Reverse engineering the question: Eight people fit in a row on an airplane, and there are 12 rows. Only 3/4 of the seats in each row are allowed to be seated. How many seats will not be occupied on that plane?
We let x be the amount of money she put in the bank the first year,. Then the second year was 2 * x,. and the third year was 2 * 2 * x = 4 * x,. and the fourth year was 2 * 2 * 2 * x = 8 * x. And the total amount she put in the bank, $450, is the sum of all four years, or $450 = x + (2 * x) + (4 * x) + (8 * x). This simplifies to $450 = 15 * x. And therefore, the amount of money she put in the bank the first year was x = $30.
The answer: 30
Reverse engineering the question:
Missy had a giant piggy bank in her bedroom. Every day she would search the house for change to put in her bank. After 4 years, the bank was opened and it contained $450 in change. If the second, third, and fourth-year she doubled the amount of money she put in the bank from the amount she had put in the previous year, how much money, in dollars, did she put in the bank the first year?