A farm used two harvesting machines, H and K, to harvest 100 acres of wheat. Harvesting machine H, working alone at its constant rate, harvested 30 acres of wheat in 8 hours. Then harvesting machine K was brought in, and harvesting machines H and K, working together at their respective constant rates, harvested the remaining acres of wheat in 7 hours. Harvesting machine K harvested how many acres of wheat per hour?\nOptions:\n(A)  7\n(B)  8\n(C)  12\n(D)  3\n(E)  15 Stream of consciousness first, then make a decision:
User
Rate of H = 7 acres/hr\nRemaining land to be harvested = 100 - 30 = 70\nRate of H and K = 70/7 = 10 acres/hr\nRate of K = 10 - 7 = 3
Thus, the answer is (D).
Assistant