Question 331753
.15(400) +1x=.32(400+x):   1=100% x=amount of prue alcohol needed
60+x=120+.32x: subtract 60 from both sides
x=60+.32x:    subtract .32x from both sides
.68x=60;       divide by .68
x=60/.68;   simplify
x=88.235ml at least