15% of 200 is 30. 30 out of 200 is 15%. A rise from 200 to 230 is a 15% increase.
The one that trips people up is percent change: always divide by the starting number, not the ending one. A price that drops from 250 to 200 fell 20%, even though climbing back from 200 to 250 takes a 25% rise.
Pure math, no tricks. Double-check the important ones.
Figured Out