[Question]Ivy drinks 2.5 liters of water each day. How many bottles of 2-liter water should Ivy buy for her 4 days consumption?
[Answer]For 4 days, Ivy consumes 2.5 x 4 = 10 liters of water. So Ivy should buy 10 / 2 = 5 bottles of 2 - liter water. The answer is 5.

[Question]Reese has been practicing piano for four hours every week. How many hours will he practice after five months?
[Answer]If Reese practices 4 four hours every week, in a month, with four weeks, he would have practiced for 4 * 4 = 16 hours. In five months, Reese would have practiced for 5 * 16 = 80 hours. The answer is 80.

[Question]Every 2 years, the number of swans at Rita's pond doubles. Currently, there are 15 swans in the pond. How many swans will there be in ten years?
[Answer]If currently there are 15 swans in the pond, in two years' time there will be 15 * 2 = 30 swans. In another two years, the number of swans in the pond will double to 2 * 30 = 60 swans. In another two years, the number of swans in the pond will double to 2 * 60 = 120 swans. If after 6 years there are 120 swans in the pond, in eight years times there will be 2 * 120 = 240 swans. In another two years, which is 10 years, there will be 2 * 240 = 480 swans in the pond. The answer is 480.

[Question]Zoe made a total of $8,000 cleaning pools and babysitting. She babysat Julie three times as often as she babysat Zachary. The number of times she babysat Zachary was 1/5 the number of times she babysat Chloe. If Zoe made $600 babysitting Zachary, how much did she earn from pool cleaning?
[Answer]
From babysitting Julie, Zoe made 3 * 600 = 1800 dollars, since she made $600 babysitting Zachary and she babysat Julie three times as often. Since she babysat Zachary 1 / 5 as often as she babysat Chloe, she made an additional 5 * 600 = 3000 dollars from babysitting Chloe. All together, the babysitting sessions made Zoe 600 + 1800 + 3000 = 5400 dollars. Subtracting babysitting payments from the total gives 8000 - 5400 = 2600 dollars. Zoe therefore made 2600 dollars cleaning pools. The answer is 2600.