Question

The speed of the boat in still water is 12 km/hr and the speed of the stream is 2 km/h. a distance of 8 km, going upstream, is covered in

Answer 1

Time = Distance/ speed . 8/12-2hr = 0.8hours or 48minutes.

Answer 2

Given:

Speed of boat=12 km/hr

Speed of stream=2 km/hr

Distance=8km

To find:

The time to cover 8km upstream

Solution:

The required time to cover 8km upstream is 48 minutes.

Since the given boat and the stream move in opposite directions when going upstream, the speed upstream is the difference between the boat's and stream's speed.

We will use the given values to calculate the speed upstream and then, the required time.

So, the upstream speed=Boat's speed- Stream's speed

Using the values,

Upstream speed=12-2=10 km/hr

Now, let the required time be T.

The time required can be obtained by dividing the distance, the speed.

T=Distance covered/ upstream speed

Using values, we get

T=8/10

T=0.8 hours

T=0.8×60 minutes

T=48 minutes

Therefore, the required time to cover 8km upstream is 48 minutes.