A man can row his boat with the stream at 20 km/h and against the stream in 4 km/h. The man's rate is?
Answers
A) 1 kmph B) 7 kmph C) 98 kmph D) 6 kmph E) 8 kmph

Rationale: "ds = 20 us = 4 s = ? s = ( 20 - 4 ) / 2 = 8 kmph answer : e"
Answer: E