A man can row his boat with the stream at 26 km/h and against the stream in 12 km/h. The man's rate is? Pick one
A) 1 kmph B) 4 kmph C) 5 kmph D) 7 kmph E) 8 kmph

Rationale: "ds = 26 us = 12 s = ? s = ( 26 - 12 ) / 2 = 7 kmph answer : d"
Answer: D