Question

A boat sails a distance of 44 km in 4 hours with the current. It takes 4 hours 48 minutes longer to cover the same distance against the current. Find the speed of the boat in still water and the speed of the current.​

Answer 1

Answer:

Step-by-step explanation:

Let the speed of the boat in still water be 4 km/hr and speed of stream be vkm/hr.

Speed down the stream =u+v

Speed against the stream =u–v

Now,Downstream distance =Speed down the stream× Time taken

⇒40=2(u+v)  

⇒u+v=20

⇒u=20–v

Upstream distance=Speed against the stream× Time taken

⇒40=(u–v)×4

⇒u–v=10

⇒20–v–v=10

⇒20–2v=10

⇒2v=20–10

⇒2v=10

⇒v=5 km/hr

u=20–5=15 km/hr

Thus speed of the boat in still water is 15 km/hr and speed of stream is 5 km/hr.