Q:

Four runners started running simultaneously from a point on a circular track. They took 200 seconds, 300 seconds, 360 seconds and 450 seconds to complete one round. After how much time do they meet at the starting point for the first time? 

• 1
  3600 sec.
• 2
  2400 sec.
• 3
  1800 sec.
• 4
  4800 sec.