There were two granaries A and B. in the past, warehouse B stored 1 / 5 less grain than warehouse A. now, 1 / 4 of warehouse A's stock is put into warehouse B, and then 30 tons are transported from warehouse B. at this time, the two granaries stored grain together (don't use equations)
+----+----+----+----+----+ 1
+----+----+----+----+ 1-1/5
+----+----+----+--- 1-1/4
+----+----+----+----+----+- 1-1/5+1/4
|30 tons|
A:
30÷[(1-1/5+1/4)-(1-1/4)]
=30÷(1/2-1/5)
=100
B: 100x (1-1 / 5) = 80