Percentage of increase = 300%
Initial amount = $25
So amount of increase = (300/100) * 25
= 3 * 25
= 75 dollars
Then the final amount = (25 + 75) dollars
= 100 dollars
I hope this is the answer you were looking for. The procedure should also be absolutely clear to you. It is always possible to solve similar problems using this easy procedure. In future I hope you will not require help from anyone for solving such problems.