Two cyclists begin training on an oval racecourse at the same time. The profesional cyclist completes each lap in 4 minutes;the novice takes 6 minutes to complete each lap. how many minutes after the start will both cyclists pass at exactly the same spot where they began to cycle?
a)10
b)8
c)14
d)12

• SHORT CUT IS L.C.M. OF 4 AND 6... IS 12 ANS IS D
• 12 years agoHelpfull: Yes(76) No(3)
• Prof. cyclist takes 4 mins to complete a lap.
  Novice takes 6 mins to complete a lap.
  Prof. cyclist takes 4 mins for 1st lap, 8 mins for 2 laps, 12 mins for 3 laps and so on.
  Similarly, novice takes 6mins for the 1st lap, 12mins for 2 laps, 18mins for 3 laps and so on.
  So they both meet at the starting point at the 12th min again.
  
• 12 years agoHelpfull: Yes(74) No(6)
• Least common multiple of 4&6 is 12.And hence the ans is 12
• 10 years agoHelpfull: Yes(3) No(1)