In What proportion must flour at $0.8 per pound be mixed with flour at $0.9 per pound so that the mixture costs $0.835 per pound?  Choose the correct answer.
A) 1:3 B) 1:2 C) 1:1 D) 2:1 E) 3:1
Using weighted average method:   Let x be the proportion in which the $0.8 per pound flour is mixed with $0.9 per pound flour.   Thus 0.8*x + 0.9*(1-x) = 0.835   0.9 – 0.1x = 0.835   x = 0.65   Thus ratio of both flours is 2:1   2:1
<result>D</result>
In What proportion must flour at $0.8 per pound be mixed with flour at $0.9 per pound so that the mixture costs $0.835 per pound?