Three monkeys ate peaches in the basket. The first monkey ate a third, and the second monkey ate the rest.

The first one ate a third, the second one ate the remaining third, that is, (1- 1/3) 1/3, that is, two-ninth, and the third one ate the remaining quarter, that is, (1-kloc-0/. Therefore, the formula is 6 ÷ (1-1/3-2/9-1/9) = 18, that is, the original peach is18.