Question

A baker purchased 10 lb of wheat flour and 13 lb of rye flour for a total cost of $17.40. A second purchase, at the same prices, included 12 lb of wheat flour and 15 lb of rye flour. The cost of the second purchase was $20.40. Find the cost per pound of the wheat flour and of the rye flour.

Answer 1

wheat = $0.96 lb rye = $1.89 lb

12w + 15r = 3987 15w + 10r = 3330 r = (3330 - 15w)/10 12w + 15r = 3987 12w + 15((3330 - 15w)/10) = 3987 12w + (15/10)(3330 - 15w) = 3987 12w + 4995 - 22.5w = 3987 10.5w = 1008 w = 96 cents r = 189 cents.

Hope this helps mate