39 persons can repair a road in 24 days, working 5 hours a day. In how many days will 30 persons, working 6 hours a day, complete the work?	Pick:
A) 10
B) 13
C) 14
D) 15
E) 26

Rationale: "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 : : 12 : x working hours / day 6 : 5 30 x 6 x x = 39 x 5 x 24 x = ( 39 x 5 x 24 ) / ( 30 x 6 ) x = 26 . answer : e"
Answer: E