Varun and Sandeep started for a car race from the same point, in the same direction and at the same time on a circular track of length 1635 m with the speeds of 90 km/h and 108 km/h, respectively. After how much time (in s) will they meet again for the first time?

Correct option is C

Given:

Length of circular track = 1635 m

Speed of Varun = 90 km/h

Speed of Sandeep = 108 km/h

Formula Used:

Speed = $$\frac{Distance}{Time}$$​​

For changing km/h to m/s, multiply by $$\frac{5}{18}$$​.

Relative speed when moving in same direction = u - v

Solution:

Speed of Varun = 90 km/h = $$90\times \frac{5}{18}=25 m/s$$​​

Speed of Sandeep = 108 km/h = $$108\times \frac{5}{18}=30m/s$$​​

Relative speed = Sandeep's speed - Varun's speed

Relative speed = 30 - 25 = 5 m/s

Now, Time taken to meet again for the first time = $$\frac{1635}{5}=\bf 327$$​ seconds.