A motor boat takes 12 hours to go downstream and it takes 24 hours to return the same distance. what is the time taken by boat in still water?  Pick one:
A) 26 h	B) 16 h	C) 86 h	D) 96 h	E) 66 h
Explanation:   If t1 and t2 are the upstream and down stream times. Then time taken in still water is given by   \inline \frac{2\times t1\times t2}{t1+t2}=\frac{2\times 12\times 24}{36}=16h   Answer: 16 h
<result>B</result>
A motor boat takes 12 hours to go downstream and it takes 24 hours to return the same distance. what is the time taken by boat in still water?