Question 614185
    A contractor mixes concrete from bags of pre-mix for small jobs. How many bags with 8% cement should he mix with 24 bags of 12% cement to produce a mix containing 10% cement?
.
Let x = bags of 8% cement added
then
.08x + .12(24) = .10(x+24)
.08x + 2.88 = .10x+2.4
2.88 = .02x+2.4
.48 = .02x
24 bags = x