Take a container with water, pour out the original (1/2) for the first time, pour out the remaining (1/3) for the second time, pour out the remaining (1/4) for the third time, and pour out the remaining (1/4) for the fourth time. Pour off the remaining (1/5). Continue in turn, after pouring how many times, the remaining water is exactly (1/10) of the original water.
将一个装有水的容器，第一次倒去原有的(1/2)，第二次倒去剩余的(1/3)，第三次倒去剩余的(1/4)，第四次倒去剩余的(1/5)．依次继续下去，在倒多少次后，剩余的水恰好是原来的水的(1/10)．
<result>9</result>