Lets take help of some numbers..
Initially the cost of the house was 100.
After that the cost increased to 300% which is 300.
Now Question is asking by what % did the cost increase?
Formula of change of %= (300-100)/100 *100= 200 or 200%.
Initially the cost of the house was 100.
After that the cost increased to 300% which is 300.
Now Question is asking by what % did the cost increase?
Formula of change of %= (300-100)/100 *100= 200 or 200%.