Two sacks together contained 40 kilograms of sugar. If after 1 kilogram of sugar was taken from the first sack and poured into the second the weight of the sugar in the first sack became 60% the weight of the sugar in the second, what was the original difference in the weights of the sacks?  Pick one:
A) 4  B) 6  C) 8  D) 10  E) 12

Rationale: say the weight of the second sack after change is x kilograms , then the weight of the first sack after change would be 0.6 x . since the total weight of sugar in both sacks remained the same then x + 0.6 x = 40 , which gives x = 25 . now , if the weight of the second sack after change is 25 kilograms then initially it was 25 − 1 = 24 kilograms and the initial weight of the first sack was 40 − 24 = 16 kilograms , so the difference was 24 − 16 = 8 kilograms . answer : c
Answer: C