The speed of the boat in still water in 12 kmph. It can travel downstream through 54 kms in 3 hrs. In what time would it cover the same distance upstream?	Select:
A) 8 hours  B) 6 hours  C) 4 hours  D) 5 hours  E) 9 hours

Rationale: "still water = 12 km / hr downstream = 54 / 3 = 18 km / hr upstream = > > still water = ( u + v / 2 ) = > > 12 = u + 18 / 2 = 6 km / hr so time taken in upstream = 545 / 6 = 9 hrs answer : e"
Answer: E