# On a river, a boat travels.64 km downstream in 2 hrs.and returns 54 km upstream in 3 hra what is the rate of the river's flow?

1
by l0l

Log in to add a comment

by l0l

Log in to add a comment

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.

Let **b** be the *speed* of the boat ;

**c** be the *speed* river's flow (aka current)

Remember that**distance = speed x time**

When the boat travels downstream, it**goes** **with the ****current**. Thus, its *speed *is increased.

The downstream travel is represented by the equation

**2 (b+c) = 64 **(2 hours is the amount of time it traveled; 64 is the total distance traveled)

On the other hand, when it travels upstream, the boat**goes against the current**. Thus, its speed is decreased. This is shown by the equation

**3 (b-c) = 54** (it took 3 hours to travel 54 km)

We now have a system of equation with two variables.

**2b + 2c = 64 ––> b + c = 32**

**3b - 3c = 54 ––> **__b - c = 27__

** 2b = 59**

b = 59/2 = 29.5

c = 2.5

Therefore, the rate of the river's flow is 2.5 km/hour

Remember that

When the boat travels downstream, it

The downstream travel is represented by the equation

On the other hand, when it travels upstream, the boat

We now have a system of equation with two variables.

b = 59/2 = 29.5

c = 2.5

Therefore, the rate of the river's flow is 2.5 km/hour