In a circular race of 2,700 m, P and Q start from point A in opposite directions at speeds of 23 km/h and 49 km/h, respectively. What is the time taken by them to meet for the first time?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 135 sec
Time = Distance/Relative speed
⇒So, Relative speed = 23km/h + 49km/h = 72km/h
The distance of the circular race is 2700m
Convert relative speed in m/s
⇒Relative speed = 72km/h × 1000m/3600sec = 20m/s
Time = distance/relative speed
= 2700m/20mps = 135 second
Hence 135 sec.