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 the correct choice from the following answers:
A) 11
B) 13
C) 66
D) 77
E) 88
Let the number of men initially be x. we have M1 D1 H1= M2 D2 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.   Answer: 13
<result>B</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?