Question 1105018
 How many quarts of a 50% solution of acid must be added to 20 quarts of a 20% solution of acid to obtain a mixture containing a 40% solution of acid?
:
let x = amt of the 50% solution
:
A typical mixture equation using the decimal equiv
.50x + .20(20) = .40(x+20)
.50x + 4 = .40x + 8
.50x - .40x = 8 - 4
.10x = 4
x = 4/.1
x = 40 qts of 50% solution