Question

ritu can row downstream 20km in 2 hrs and upstream 4km in 2 hrs. find the speed of rowing in still water and the speed of the current

Answer 1

Answer:

Speed of boat in still water is 6km/h

Speed of current is 4km/h

Step-by-step explanation:

We know speed = distance / time

Let the speed of boat in still water be x

Let the speed of current be y

Hence the speed of boat, down stream = $x+y$

Distance downstream = 20km

Time taken = 2 hours

We have

$x+y=\frac{20}{2}$

$x+y=10$       ......(1)

Speed of boat upstream = $x-y$

Distance upstream = 4

Time taken = 2

We have

$x-y=\frac{4}{2}$

$x-y=2$    ...(2)

Adding (1) & (2)

$2x=12$

$x=6$

Substituting in (1) we get

$y=4$