Grapes are 80% water (by weight) and raisins are 20% water (by weight). If we start with 500 grams of grapes and remove enough water to turn them into raisins, then what is the weight of the raisins?
from 80 to 20 is a reduction of 3/4 ......or only 1/4 of the original remains
500 x 1/4 = 125 gm of raisins