Ramon buys five 3 - pound bags of natural parrot food for $8.79 per bag and two 5 - pound bags for $13.90 per bag. what is the average cost per pound of parrot food?

Five 3 lb bags (5 x 3 = 15 lbs) for 8.79 per bag (5 * 8.79 = 43.95)
two 5 lb bags (2 x 5 = 10 lbs) for 13.90 per bag (2 * 13.90 = 27.80)

average cost per lb : (43.95 + 27.80) / (15 + 10) = 71.75 / 25 = 2.87
so the average cost per lb is $ 2.87