A certain number of men can do a work in 65 days working 6 hours a day. If the number of men are decreased by one-fourth, then for how many hours per day should they work in order to complete the work in 40 days? Choose one.
A) 11  B) 12  C) 14  D) 13  E) 15
D   13   Let the number of men initially be x. we have M1 131 H1= M2 132 H2   So, x * 65 * 6 = (3x)/4 * 40 * h2   =&gt; h2 = (65 * 6 * 4)/(3 * 40)= 
<gadget id="calculator">(65 * 6 * 4)/(3 * 40)</gadget>
<output>13</output>
13.
<result>D</result>
A certain number of men can do a work in 65 days working 6 hours a day. If the number of men are decreased by one-fourth, then for how many hours per day should they work in order to complete the work in 40 days?