Arun, Barun and Kir...

Share:
Clear all

# Arun, Barun and Kiranmala start from the same place and travel in the same direction at speeds of 30, 40 and 60 km per hourrespectively. Barun starts two hours alter Arun. If Barun and Kiranmala overtake Arun at the same instant, how many hours after...

(@soham)
Estimable Member

Time speed distance doubt

Topic starter Posted : 29/09/2020 6:22 pm
(@rahul)

Let us assume that Arun started running at 10 AM and Barun started at 12 noon.
So, in these two hours distance travelled by Arun is 60 km and the relative speed of Barun w.r.t Arun is 10 km/hr.
So Barun will overtake Arun after =

 60 10

=6 hrs
So, Barun reaches there at 6 PM.
So, Kiranmala also overtakes Arun at 6 PM.

Let us assume Kiranmala takes 't' time to overtake Arun and the relative speed of Kiranmala w.r.t Arun is 30 km/hr and Arun ran for 8 hrs.
So, distance travelled by Arun is:
While Kiranmala's distance travelled is:
t=4 hours

So, after 4 hrs, Kiranmala will start running

Posted : 29/09/2020 6:23 pm
Share: