florence bought two bags of flour, A and B. the two bags contained different amounts of flour. the total mass was 108 kg. Gary poured 1/4 of the flour from bag A to bag B. After that, he poured 2/5 flour from bag B to bag A. he found that the both bags had the same mass now. how much flour was there in bag B in the beginning

Answer 1

a+b=108
3a/4 + (2/5)(b+a/4) = (3/5)(b+a/4)

now just solve for b.