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?	Choose the correct choice from the following options:	A) 7	B) 8	C) 12	D) 3	E) 15
Rate of H = 7 acres/hr   Remaining land to be harvested = 100 - 30= 
<gadget id="calculator">100 - 30</gadget>
<output>70</output>
70   Rate of H and K= 70/7= 
<gadget id="calculator">70/7</gadget>
<output>10</output>
10 acres/hr   Rate of K= 10 - 7= 
<gadget id="calculator">10 - 7</gadget>
<output>3</output>
3   Answer: 3
<result>D</result>
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?