Cup A has 600 grams salt solution of 40% concentration. Cup B has 400 grams salt solution of 20% concentration. To make the concentrations of the two cups of salt solution equal, how many grams of salt solution should the two cups exchange with each other?
I don't know what to do.
A salt = 40% * 600 = 240 g
B salt 20% * 400 = 80 gm
There will be 1000 gm of salt solution at the end of mixing
240g + 80 g = 1000 (x%)
320 = 1000 x final solution will be 32%
Let 'x' be the amount to pour off of the 4% solution this will be the same amount of 2% solution to be added back in to make 600 gm of 32%
.4 (600-x) + .2(x) = 600 (.32)
pour off 240 ml from each and add it to the other ..... you will have 600 gm of 32% and 400gm of 32%