Question

A boat travels downstream for 14km and upstream for 9km. if the boat took total of 5 hours for its journey. what is the speed of the river flow if the speed of the boat in still water is 5km/hr?

Answer 1

It is

14/5+x + 9/5-x=5.
It is

X=1

Answer 2

Answer:

The speed of the stream will be 2 km/hr.

Explanation:

Given that,

Distance downstream = 14 km

Distance upstream = 9 km

Total time = 5 hours

Speed of the boat = 5 km/h

Let us considered the speed of the stream be x km/h.

Upward speed  = (5-x) km/h

Downward speed = (5+x) km/h

The time is

$t_{1}+t_{2}=5$

Where, t₁ = time of downstream

t₂ = time of upstream

$\dfrac{14}{5+x}+\dfrac{9}{5-x}=5$

$70-14x+45+9x=125-5x^2$

$x^2-x-2=0$

$x = 2\ km/h$

Hence, The speed of the stream will be 2 km/hr.