Two runners, Sony and Mony, start running on a circular track of length 200 m at speeds of 18 and 24 km/h, respectively, in the same direction. After how much time from the start will they meet again at the starting point?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e 120 sec.
Relative speed = 24 - 18 = 6 km/hr = 6 × 5/18 = 5/3 m/sec
Relative speed = distance/time
5/3 = 200/time
time = 200 × 3/5 = 120 sec