Suppose a has x, then b has 40-x tons.
When 4 tons of water is injected into pool A, 8 tons of water is discharged from pool B..
The water storage capacity of the two pools is equal.
therefore
x+4=40-x-8
Get x= 14.
40- 14=26
So the original two pools stored 14 and 26 tons of water respectively.
*** 1 15 members of a school actively participated in fund-raising activities. Some members each donated 10 yuan, and the rest did not give to 4 yuan. If the total donation amount is 790 yuan, how many members donated 10 yuan?
Member X donated money 10 yuan, and member (1 15-X) donated money to 4 yuan.
10X+4×( 1 15-X)= 790
X=55