Question

a motor boat goes downstream and cover a distance in 4hours while it covers the same distance upstream in 5hours. If the speed of the stream is 3km/hr find the speed of the motor boat in still water. ​

Answer 1

Answer:

Step-by-step explanation:

Given:-

A motor boat goes downstream and cover a distance in 4 hours while it covers the same distance upstream in 5 hours.

If the speed of the stream is 3km/hr.

To Find :-

Speed of the motor boat in still water.

Formula to be used :-

Distance = Time × Speed

Solution :-

Let the speed of the boat in still water be x.

Distance of downstream in a hour = x + 3

Distance of upstream in a hour = x - 3

According to the question,

Distance of downstream in 4 hrs = 4x + 12

Distance of upstream in 5 hrs = 5x - 15

Solving both downstream and upstream

⇒ 4x + 12 = 5x - 15

⇒ 12 + 15 = 5x - 4x

⇒ 27 = x

Hence, the Speed of the motor boat in still water 27 km/h.