Question

The speed of a boat in still water is 30 km/h . It takes same time for boat to travel for boat to travel 5 km upstream as it does to travel 10 km downstream . Find speed of stream

Answer 1

Answer:

Refer to the attachment. enjoy!

Answer 2

Given,

Speed of the boat in water = 30km/h

Distance traveled by boat to upstream = 5km

Distance traveled by boat to downstream = 10km

To Find,

The speed of the stream.

Solution,

Let's take stream speed = S km/h

Therefore,

The speed of the boat, upstream =

(S+30) km/h

The speed of the boat, downstream =

(30-S)km/h.

The boat travels the distance upstream = 5km.

Distance traveled downstream = 10km.

Time is taken to travel = $\frac{distance}{speed}$

Apply the equation to find time here,

Here, both upstream and downstream boat takes the same time.

$\frac{5}{30+S}$ = $\frac{10}{30-S}$

5(30-S) =10(30+S)

150-5S=300 +10S

15S =  150

S = 150/15

S =10km/h

Hence, the speed of the stream is 10km/h.