Speed of a boat in standing water is 16 kmph and the speed of the stream is 2 kmph. A man rows to a place at a distance of 6840 km and comes back to the starting point. The total time taken by him is: Choose the correct choice
A) 914.2 hours	B) 900 hours	C) 915 hours	D) 868.6 hours	E) 915 hours

Rationale: "explanation : speed downstream = ( 16 + 2 ) = 18 kmph speed upstream = ( 16 - 2 ) = 14 kmph total time taken = 6840 / 18 + 6840 / 14 = 380 + 488.6 = 868.6 hours answer : option d"
Answer: D