Question

A boat moves downstream at the rate of 8 kmph and upstream at a rate of 5 kmph. the speed of the boat in still water is

Answer 1

let the actual speed of boat be x
the speed of the current be y
when the boat goes upstream
x-y=5
when the boat goes downstream
x+y=8
adding both equation, we get
2x=13
x=6.5kmph

Answer 2

Answer:

The speed of the boat in still water is 6.5 kmph.

Step-by-step explanation:

The speed of the boat in still water is the average speed of boat in upstream and downstream.

$\text{speed of the boat in still water}=\frac{\text{speed of boat in upstream+speed of boat in downstream}}{2}$

It is given that the boat moves downstream at the rate of 8 kmph and upstream at a rate of 5 kmph.

The speed of the boat in still water is

$S=\frac{5+8}{2}=\frac{13}{2}=6.5$

Therefore the speed of the boat in still water is 6.5 kmph.