51 persons can repair a road in 12 days, working 5 hours a day. In how many days will 30 persons, working 6 hours a day, complete the work?  Pick one.
A) 10  B) 13  C) 14  D) 15  E) 17
According to the chain rule,   M1 x T1 = M2 x T2   Therefore, 51 x 12 x 5 = 30 x 6 x X   X = 17   Hence, the number of days = 17.   ANSW17R:17
<result>E</result>
51 persons can repair a road in 12 days, working 5 hours a day. In how many days will 30 persons, working 6 hours a day, complete the work?