8-2=6 minutes and 5-3=2 inches so it lost 2 inches in 6 minutes. This means it loses an inch every three minutes. Since we have to go back by 2 minutes we will have to figure out how much length we have to add to the candle to figure out how long it was originally by multiplying by 2/3 as 2 inches is 2/3 the required to remove an inch, so 1 inch * 2/3 = 2/3 of an inch. Add that to the length at two minutes and we have 5 2/3 inches as its original size.
Each one would be 5 minutes because 2 1/2 Times 4 = 10 minutes. You would have 20 minutes remaining so divide 20 by how many segments there are, which is 4 to get 5