Question

A boat went down the river for a distance of 20 km. it then turned back and returned to it starting point, having travelled a total of 7 hours. on its return trip, at a distance of 12 km from the starting point, it encountered a log, which had passed the starting point at the moment at which the boat had started downstream. the downstream speed of the boat is?

Answer 1

Here's your answer frd:

Hope This Helps :)

Answer 2

Answer:

Speed of the boat in the downstream is 10 km/hour

Step-by-step explanation:

Let x be the speed of the water in still water and y be the speed of the stream.

Also, the time taken by the boat in travelling {d + (d - 12)} Km , the boat after lag travels 12 km

$\implies\frac{12}{y}=\frac{20}{x+y}+\frac{8}{x-y}.......(1)$

Also, it traveled a total of 7 hours on the return

$\implies \frac{20}{x+y}+\frac{20}{x-y}=7.......(2)$

We need to find the value of (x + y)

Now, solving equations (1) and (2) , We get

x + y = 10

Therefore, Speed of the boat in the downstream is 10 km/hour