This problem is easy, as 10 is one of the numbers involved. We'll set it up like this:
The percent increase from 10 to 10 is 0%
The percent increase from 10 to 20 is 100%
The percent increase from 10 to 15 is 50%.
Notice a pattern?
Using this pattern, we can tell that the percent increase from 10 to 14 is 40%
Hope this helps! (:
