Question

Ram rows a boat at a speed of $15$ kmph upstream and $20$ kmph downstream. Find the speed with which he rows the boat in still water

• A. $\frac{5}{2}$
• B. $\frac{15}{2}$
• C. $10$
• D. $\frac{35}{2}$

Answer 1

The correct option is D $\frac{35}{2}$

$\left(U\right)$ Speed of boat upstream=$15$km/hr

$\left(D\right)$ Speed of boat downstream=$20$km/hr

$\therefore$ Speed of boat in still water=$\frac{U+D}{2}=\left(\frac{15+20}{2}\right)$km/hr

$\frac{35}{2}$km/hr.