49 pumps can empty a reservoir in 13/2 days, Working 8 hours a day. If 196 pumps are used for 5 hours each day, then the same work will be completed in:  Answers: A) 2 days B) 5 / 2 days C) 13 / 5 days D) 3 days E) none of these

Rationale: explanation : let the required number of days be x . then , more pumps , less days ( indirect proportion ) less working hrs / day , more days ( indirect proportion ) pumps 196 : 49 working hrs / day 5 : 8 : : 13 / 2 : x 96 x 5 x x = 49 x 8 x 13 / 2 x = 49 x 8 x 13 / 2 x 1 / ( 196 x 5 ) x = 13 / 5 answer c
Answer: C