# Each time a bar of soap is used, its volume decreases by #10%#. What is the minimum number of times a new bar would have to be used so that less than one-half its volume remains?

##### 1 Answer

Oct 18, 2017

7 times

#### Explanation:

The formula for this equation would be

Dividing both sides by

Taking the log of both sides gives

It can be used 7 times before less than half of its volume remains.