A man can row his boat with the stream at 6 km/h and against the stream in 3 km/h. The man's rate is? Choose the correct option
A) 1.5 kmph
B) 3 kmph
C) 8 kmph
D) 7 kmph
E) 5 kmph

Rationale: "ds = 6 us = 3 s = ? s = ( 6 - 3 ) / 2 = 1.5 kmph answer : a"
Answer: A