Question

in 1 hour a boat travel 9 km in upsterm.it takes the same time to travel 15 km in downstream.find the speed of the strem​

Answer 1

refer to the above solution .. hope u will get it

Answer 2

Step-by-step explanation:

Let the speed of the boat in still water be x km/hr and that is the stream be y km/hr.

upstream= (x-y) km/hr

downstream= (x-y) km/hr

9/x+y = 1

x+y = 9 -------------(i)

15/x-y = 1

x-y = 15 -------------(ii)

(i) + (ii)

x+y = 9

x-y = 15

2x = 24 -------------- ÷2

x = 12 ------------(iii)

subsituting (iii) in (i)

12 + y = 9

y = 3

So , the speed of the boat in still water is

12 km/hr.

And the speed of stream is 3 km/hr.