Question

Krishna can run 2 kilometres in 10 minutes how long will it take him to run a marathon of 48 km

Answer 1

speed of krishna in 10 minutes = 2000 m 
so speed of krishna in 1 min = 200 m = 20/6 m/s 

So, Time taken to run 48000 m = 20/6* 48000 s
                                                  = 16000 s

Answer 2

Heya,

According to the question,

Krishna can run 2km in 10mins.

So, We can say that
Time taken for Krishna for 1km = 10/2 = 5mins

Now,
Time taken by Krishna to run a marathon of 48km = 5×48
= 240mins

We will convert 240min into hrs.
Then, 240min = 240/60 hrs = 4hrs

So, it will take 4 hrs long for him to run a marathon of 48km.

Hope this helps....:)