To solve it first you need to find what 18% of 200 is. To do that take the 18% and make it a decimal % is out of 100, so 18/100 = .18. Then to find how much 18% out of 200 is, multiply .18 * 200. You should get 36. Then you can add and subtract that from 200 to get 18% more and 18% less.
