Question

a man can swim downstream at 10 km per hour and upstream at 4 km per hour find the speed of the man in still water and the speed of the current respectively​

Answer 1

Answer:

Speed of man in still water be 7 km/hr

Speed of the current be 3 km/hr

Step-by-step explanation:

Let the speed of man in still water be x km/hr

Let the speed of the current be y km/hr

Speed in upstream = (x - y) km/hr

Speed in downstream = (x + y) km/hr

Also, distance, speed and time are related as below

Distance = Speed × Time

Now, given that man can swim downstream at 10 km/hr

Thus, we have

x + y = 10 ---- (1)

Also, man can swim at 4 km per hour in upstream

Thus, we have

x - y = 4 ---- (2)

Solving (1) and (2), we get

 x + y = 10

 x - y = 4

--------------------

 2x = 14

   x = 14/2

   x = 7

Putting the value of x in (1), we get

  7 + y = 10

   y = 10 - 7

   y = 3

Speed of man in still water be 7 km/hr

Speed of the current be 3 km/hr