Question 972969
x=liters of 48% solution
The trick in this is to remember the final solution is going to be 40 liters (the other part) +x added.

.48x +40(.35)=(40+x)*0.40

.48x + 14 =16 + 0.40x
0.08x =2
8x=200
x=25 liters

total solution is 65 liters
65(.40)=26   .48(25)=12  and 40 (.35)=14

25 liters of a 48% solution