Find the speed of the stream from the speed of the man given in both upstream and downstream

A boat takes N1 hr to row a bot X1 km downstream of a river and take N2 hr to cover a distance of X2 km upstream. Find the speed of the stream.

Input: 3 15 2 5
Output: 17.5 km/hr

Input: 4 29 7 30
Output: 47 km/hr


  • Take input from users
  • Calculate the rate of downstream and upstream. The rate can be calculated using the formula.

Speed = \frac{distance}{time}

  • Then, calculate the speed of the stream. It is given by the formula – 

Rate of Stream = \frac{1}{2}(downstream - upstream)

Below is the implementation.






def rate(down, up):
    # stream rate
    rate = 0.5*(down - up)
    print(rate, " Km/hr")
# Driver Code
# Distance and time downstream
N1 = 3
X1 = 15
# Distance and time upstream
N2 = 2
X2 = 5
# Rate of downstream and upstream
Rate_downstream = X1/N1
Rate_upstream = X2/N2
rate(Rate_downstream, Rate_upstream)



1.25  Km/hr

My Personal Notes arrow_drop_up

Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using or mail your article to See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.

Article Tags :

Be the First to upvote.

Please write to us at to report any issue with the above content.