Question

a boat covers a certain distance downstream in 2 hours. It covers the same distance upstream in 2.5 hours. The speed of the boat in still water is 18 km/h .find the speed of the water. also find the distance covered by the boat ​

Answer 1

Speed of boat in still water be u km/hr.  

Then, distance covered downstream =(u+1)×2=8u+8

Distance covered upstream =(u−1)×2.5=2.5u−2.5

Since the distance both ways is the same,  

2u+2=2.5u−2.5

⇒4.5=0.5u

⇒u=9 km/hr

∴ Distance covered one way =(9+1)×8 km

=80 km