Answer:
Option A
Explanation:
Let speed of rowing in still water $=x$ km/h
Speed of stream = 2 km/h and total time $=\frac{55}{60}$ hrs
Total Time = $\frac{Total\quad Distance} {Average\quad Speed}$
= Total Distance / ((Upstream rate$\times$ Downstream rate)/ Speed in still water)
$\frac{55} {60}$ = $\frac{x\times 2\times 10} {(x+2)(x- 2)}$
$x$ = 22 (negative value of $x$ is not possible)
Speed of rowing in still water = 22 km/h
