64+8x=57+9x

64-57=x

x=7

A: After 7 days, the grain storage capacity of warehouse B is twice that of warehouse A. ..

2. Solution: (100x/100+400x/2/100+1000 *15/100)/(/kloc)

= 14/ 100x

=20

A: The concentration of methanol solution is 20%.

3. Solution: x+25%x=y+ 1/9y

x+y=8500

x=4000

y=4500

A: A has 4,000 yuan and B has 4,500 yuan.