A man swims downstream 30 km and upstream 18 km taking 3 hours each time, what is the speed of the man in still water?	Pick one
A) 3
B) 8
C) 9
D) 4
E) 2

Rationale: 30 - - - 3 ds = 10 ? - - - - 1 18 - - - - 3 us = 6 ? - - - - 1 m = ? m = ( 10 + 6 ) / 2 = 8 answer : b
Answer: B