RRB Junior Engineer / DMS / CMA 2019 · Question 3110 of 3719

To row a certain distance upstream and downstreamtakes $$t_1$$ hours and $$t_2$$ hours respectively and speed of stream is 'y' km/h. Find speed in still water.

1. A$$ \left(\frac {t_1 ^2 - t_2 ^2} { 2y}\right) km/h $$
2. B$$ \left[\left(\frac {t_1 - t_2 } { t_1 + t_2}\right) y \right ]km/h $$
3. C$$ \left[ \frac{(t_1 + t_2 ) 2y}{ ( t_1 - t_2)} \right ]km/h $$
4. D$$ \left[ \frac{(t_1 + t_2 )}{ ( t_1 - t_2) }y \right ]km/h $$Correct