Q:

P, Q and R start at the same time in the same direction to run around a circular stadium. P completes a round in 252 seconds, Q in 308 seconds and R in 198 seconds, all starting at the same point. After what time will they next meet at the starting point again? 

• 1
  42 minutes 36 seconds
• 2
  26 minutes 18 seconds
• 3
  46 minutes 12 seconds
• 4
  45 minutes