CC.14 Exchange salt solution between two

There are two salt solution with different salt concentration in the two beakers A and B, respectively.
The ratio of the weight of the salt solution of A and B is 2 : 3.
The following two operation are done 1 time respectively in order.

- Move the half of the salt solution of A to B, and stir it well.
- Move the half of the salt solution of B to A, and stir it well.

The ratio of the salt concentration of the salt solution of A and B after two operations is to be 4 : 5.
Salt concentration of salt solution is the rate of the weight of the salt based on the weight of a salt solution.

(1) Find the ratio of the weight of the salt solution of A and B after two operations.

(2) When the salt concentration of the salt solution of A at first is 4%, find the salt concentration of the salt solution of B at first.




Answer
(1) 3 : 2
(2) 12 %