Question

A chemistry student needs to make 60 liters of a 30% alcohol solution. He has a 20% alcohol solution and a 40% alcohol solution in the lab. How many liters of each strength does he need to mix together

*The system of equations I did was: a+b=60 & .2a+.4b=18. I may be wrong but i seriously need help

Answer 1

You are seriously right in your equations.

Answer 2

then a = (60-b)

.2(60-b) + .4 b = 18
12 - .2 b + .4 b = 18
.2 b = 6
b = 30
a = 30