Question

A streamer covers the distance between two parts in 3 hours when it goes downstream and 5 hours when it goes upstream. Find the speed of the streamer upstream if the stream flows at 3 km/h.

Answer 1

Answer:

The speed of the streamer when it goes upstream is 9 km/h.

Step-by-step explanation:

We are given that a streamer covers a distance between two places in 3 hours when it goes downstream and in 5 hours when it goes upstream. The speed of the stream is said to be 3 km/h.

Let the distance between the two places be x.

We have, Upstream speed $= \frac{distance}{upstream time}$

⇒ Upstream speed $= \frac{x}{5} km/h$

Similarly, the downstream speed $= \frac{x}{3} km/h$

We know,

2 * Speed of current = Downstream speed - Upstream speed

⇒ $2*3$ = $\frac{x}{3} - \frac{x}{5}$

⇒ $6 = \frac{5x - 3x}{15} = \frac{2x}{15}$

⇒ $x = 45 km$

Hence, Upstream speed of streamer $= \frac{45}{5} = 9km/h$

Answer 2

The speed of the streamer when it goes upstream is 9 km/h.

Step-by-step explanation:

We are given that a streamer covers a distance between two places in 3 hours when it goes downstream and in 5 hours when it goes upstream. The speed of the stream is said to be 3 km/h.

Let the distance between the two places be x.

We have, Upstream speed = \frac{distance}{upstream time}=

upstreamtime

distance

⇒ Upstream speed = \frac{x}{5} km/h=

5

x

km/h

Similarly, the downstream speed = \frac{x}{3} km/h=

3

x

km/h

We know,

2 * Speed of current = Downstream speed - Upstream speed

⇒ 2*32∗3 = \frac{x}{3} - \frac{x}{5}

3

x

−

5

x

⇒ 6 = \frac{5x - 3x}{15} = \frac{2x}{15}6=

15

5x−3x

=

15

2x

⇒ x = 45 kmx=45km

Hence, Upstream speed of streamer = \frac{45}{5} = 9km/h=

5

45

=9km/h