The Speed of a boat in still water is 25 kmph. If it can travel 10 km upstream in 1 hr, What time it would take to travel the same distance downstream? Choose the correct choice from the following:
A) 26 minutes B) 23 minutes C) 15 minutes D) 19 minutes E) 28 minutes

Rationale: speed of boat in still water = 25 km / hr speed upstream = 10 ⁄ 1 = 10 km / hr speed of the stream = ( 25 - 10 ) = 15 km / hr speed downstream = ( 25 + 15 ) = 40 km / hr time taken to travel 10 km downstream = 10 / 40 hours = ( 10 × 60 ) / 40 = 15 minutes answer is c
Answer: C