Question

Do help me .. And answer this .. ◉‿◉​

Answer 1

Answer:

8km/h

Step-by-step explanation:

Let speed of the boat in still water =x km/hr, and

Speed of the current =y km/hr

Downstream speed =(x+y) km/hr

Upstream speed =(x−y) km/hr

T= D/S

24. =. + 16. = 6 ...........(1)

x+y. x-y

36. +. 12. = 6 ............(2)

x+y. x-y

Put

1. = u

x+y

and

1. = v

x−y

the above equation becomes,

24u+16v=6

Or, 12u+8v=3 ... (3)

36u+12v=6

Or, 6u+2v=1 ... (4)

Multiplying (4) by 4, we get,

24u+8v=4v … (5)

Subtracting (3) by (5), we get,

12u=1

⇒u=

12

1

Putting the value of u in (4), we get, v=

4

1

⇒

x+y

1

=

12

1

and

x−y

1

=

4

1

⇒x+y=12 and x−y=4

Thus, speed of the boat upstream =4 km/hr

Speed of the boat downstream =12 km/hr

so the speed of boat in still water = ½×(4km/h + 12km/h) = ½×16= 8km/h