Question 186628
Let x=amount of 13.2% beer that's needed
Then 100-x=amount of 0.2% beer that's needed
Amount of pure alcohol before they are mixed=amount of pure alcohol after they are mixed, so:
0.132x +0.002(100-x)=0.08*100
0.132x+0.2-0.002x=8 subtract 0.2 from each side and collect like terms
0.130x=7.8   divide each side by 0.130
x=60 liters amount of strong beer that's needed
100-x=100-60=40 liters----amount of weak beer needed

CK
0.132*60 +0.002*40=0.08*100
7.92+0.08=8
8=8


Hope this helps----ptaylor