The speed of the boat in still water in 12 kmph. It can travel downstream through 48 kms in 3 hrs. In what time would it cover the same distance upstream? Choose the correct option
A) 8 hours
B) 6 hours
C) 4 hours
D) 5 hours
E) 6 hours

Rationale: "still water = 12 km / hr downstream = 48 / 3 = 16 km / hr upstream = > > still water = ( u + v / 2 ) = > > 12 = u + 16 / 2 = 8 km / hr so time taken in upstream = 48 / 8 = 6 hrs answer : e"
Answer: E