The original warehouse of A is X tons, and the original warehouse of B is Y tons.

( 1- 1/4)X+(X/4+Y)/4 =(X/4+Y)( 1- 1/4)

3/4X+X/ 16+Y/4 = 3/ 16X+3/4Y

5/8X=Y/2

X=4/5Y

It turns out that the grain in warehouse A is five-quarters of that in warehouse B.