Question 193629
.30*20+.80x=.5(20+x)
6+.8x=10+.5x
.8x-.5x=10-6
.3x=4
x=13.33 gal of 80% solution is needed.
Proof:
.30*20+.8*13.33=.5(20+13.33)
6+10.66=.5*33.33
16.66=16.66