In a circular race along a track of length 3600 m, X and Y run at speeds of 27 km/h and 45 km/h, respectively. Suppose they start at the same time and in the same direction, when will they meet again at the starting point?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 720 sec.
X = 27 km/h = 27000/60 = 450 m/min
Y = 45 km/h = 45000/60 = 750 m/min
Time taken by X = 3600/450 = 8 minutes
Time taken by Y = 3600/750 = 4.8 minutes
LCM of 8 and 4.8 = 120
So, LCM = 120/5 = 24 minutes.