For a motorboat that covers a certain distance downstream in 2 hours & returns in 3 hours, what would be its speed in still water if the speed of stream is 6 km/hr?
20 km/hr
25 km/hr
30 km/hr
35 km/hr
Explanation:
Speed of boat in still water=$y\left(\dfrac{t_2+t_1}{t_2-t_1}\right)km/h$
With the given parameters , y = 6 km/hr, t1 = 3 hrs, t2 = 2 hrs
We can find, Speed of boat in still water (x) = $6\left(\dfrac{3+2}{3-2}\right)$
= 30 km/hr