A man can row his boat with the stream at 6 km/h and against the stream in 2 km/h. The man's rate is? Choices
A) 1 kmph B) 2 kmph C) 5 kmph D) 7 kmph E) 8 kmph

Rationale: "ds = 6 us = 2 s = ? s = ( 6 - 2 ) / 2 = 2 kmph answer : b"
Answer: B