39 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? Answers:
A) 16
B) 19
C) 13
D) 14
E) 18
Let the required number of days be X.   Less persons, More days (Indirect Proportion)   More working hours per day, Less days (Indirect Proportion)   Persons 30	:	39   Working hours/day	6	:	5 :: 12 : X   THEREFORE 30 x 6 x X = 39 x 5 x 12   X =(39 x 5 x 12)/(30 x 6)   X = 13.   ANSWER:13
<result>C</result>
39 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?