Fresh grapes contain 90% by weight while dried grapes contain 20% water by weight. What is the weight of dry grapes available from 5 kg of fresh grapes?
Choose the correct choice:
A) 2 kg
B) 2.4 kg
C) 2.5 kg
D) 10 kg
E) 0.625

Rationale: "the weight of non - water in 5 kg of fresh grapes ( which is 100 - 90 = 10 % of whole weight ) will be the same as the weight of non - water in x kg of dried grapes ( which is 100 - 20 = 80 % of whole weight ) , so 5 â ˆ — 0.1 = x â ˆ — 0.8 - - > x = 0.625 answer : e ."
Answer: E