You need to make 225 and 187.5 into a fraction like 187.5/225 then compare that to ?/100 to that you need to figure out what 225 divided by 100 is then divide that answer by 187.5. 225/100=2.25 187.5 divided by 2.25 is 83.3. 100- 83.3= 16.7 percent. You're right if you round it