Please change your name from confused student.
We are decreasing so, we first of find 68% of 225
= 68 / 100 * 225 = 17/ 25 * 225 That is using 4 into 68 and 100
17/5 * 45 Using 5 into 25 and 225.
17 * 9 = 153.
Since we are decreasing then we are going to subtract this result from 225.
If we were increasing we would have added.
= 225 - 153 = 72.
That's our answer. Cheeers.