Alison bought some storage tubs for her garage. She bought 3 large ones and 6 small ones, for $48 total. If the large tubs cost $6, how much do the small ones cost? Give the rationale and then the answer.
Let's think step by step. Let t be the price of the small tubs. 3 * 6 + 6 * t = 48. 18 + 6 * t = 48. 6 * t = 48 - 18 = 30. 6t = 30. t = 5 dollars for each small tub.. The answer is: 5.

Giselle had 20 female doves in a birdhouse. After a month, the doves laid 3 eggs each. If 3/4 of the eggs hatched, calculate the total number of doves Giselle has now. Give the rationale and then the answer.
Let's think step by step. If Giselle had 20 doves that laid 3 eggs each, the total number of eggs in the birdhouse is 20 * 3 = 60 eggs. If 3 / 4 of the eggs hatched into birds, their total number is 3 / 4 * 60 = 45. In the birdhouse, there are 20 initial doves + 45 new squabs = 65 birds.. The answer is: 65.

The length of the straight part of a river is three times shorter than the crooked part. If the river is 80 miles long, how long is the straight part of the river? Give the rationale and then the answer.
Let's think step by step. Let's say the river's length in the straight part of the river is x. The total length of the river is the length of the straight part plus 3 times the length of the straight part for the crooked part, which is x + 3x = 80. The total length of the river is 4x = 80. The straight part of the river is x = 80 / 4 = 20 miles.. The answer is: 20.