40 g of salt solutions are in both of two beakers A and B each.
The ratio of the concentration of salt solution of A and B is 3 : 2.
I add 60 g of water to B and mixed it well and transferred some of salt solutions in B to A.
Furthermore, I add some water in both of A and B to become 100 g of salt solutions.
The ratio of the concentration of salt solution of A and B was to be 7 : 3.
Find the weight of the salt solution I transferred from B to A.
The ratio of the concentration of salt solution of A and B is 3 : 2.
I add 60 g of water to B and mixed it well and transferred some of salt solutions in B to A.
Furthermore, I add some water in both of A and B to become 100 g of salt solutions.
The ratio of the concentration of salt solution of A and B was to be 7 : 3.
Find the weight of the salt solution I transferred from B to A.
Answer
It is because the total amount of salt was never changed in the series of operation.
In other words I understand that the amount of salt transferred to A from B was 1.
Because the amount of the beginning of B was 4 and the amount after transfer was 3, 1/4 of the salt of B transferred.
1/4 of the salt solution should move for 1/4 of the salt to move.
Because the amount of the salt solution of B before the transfer was 40 + 60 = 100 g, the amount I transferred is 100 × 1/4 = 25 g.
25 g
Solution
All amount of the salt being set to 10 which is the sum of 7 and 3, as for the amount of the salt after a series of operation, the amount of salt in A is 7 and that in B is 3.
In addition, as the ratio of salt amount at the beginning was 3 : 2, the amount of salt in A was 6 and that in B was 4.
In addition, as the ratio of salt amount at the beginning was 3 : 2, the amount of salt in A was 6 and that in B was 4.
It is because the total amount of salt was never changed in the series of operation.
In other words I understand that the amount of salt transferred to A from B was 1.
Because the amount of the beginning of B was 4 and the amount after transfer was 3, 1/4 of the salt of B transferred.
1/4 of the salt solution should move for 1/4 of the salt to move.
Because the amount of the salt solution of B before the transfer was 40 + 60 = 100 g, the amount I transferred is 100 × 1/4 = 25 g.
