A man can row his boat with the stream at 26 km/h and against the stream in 4 km/h. The man's rate is?	Choose the correct answer:
A) 1 kmph
B) 7 kmph
C) 98 kmph
D) 11 kmph
E) 4 kmph

Rationale: "ds = 26 us = 4 s = ? s = ( 26 - 4 ) / 2 = 11 kmph answer : d"
Answer: D