Question

The meat department in a grocery store needs 200 lb of hamburger that is 80% lean beef. How many pounds of 78% lean and 85% lean must be mixed?

Answer 1

x+y=200
.78x + .85y = 200(.80)
.78x+.85(200-x)=160
-.07x+170=160
-.07x=-10
x=142.86 78% beef
y=57.14 85% beef