The “Racing magic” takes 120 seconds to circle the racing track once. The “Charging bull” makes 40 rounds of the track in an hour. If they left the starting point together, how many minutes will it take for them to meet at the starting point for the second time?

• @sruthi how did u got .6x in a minute :/
  i think answer is 12min
  ->man takes 2min to complete a round
  -> bull takes 40 rounds to in = 60min
  so bull takes 1 round in 60/40min=1.5min
  lcm of 1.5 and 2 is 6
  so first round in 6min and 2nd in 12min :)
• 11 years agoHelpfull: Yes(55) No(9)
• Racing magic = 120sec/1round
  = 2min/1round
  Charging bulla = 40rounds/1hour
  = 40rounds/60min
  = 1.5mins/1round
  Minutes taken Racing magic intervals::2,4,6,8.....
  to meet for :::
  the 2nd time Charing bulla intervals::1.5,3,4.5,6,7.5,...
  Time taken is 6minutes
  
• 11 years agoHelpfull: Yes(19) No(2)
• AS man takes 120 seconds(2 minutes) to cover the track once=> for one minute he tracks 0.5x (if x is the length of the track)
  
  similarly, bull makes 40 rounds in one hour (60 minutes) => it covers 0.6x per minute.
  now speeds of both would be x/0.5 and x/0.6
  
  they meet first time at x/(x/0.5 - x/0.6) = 3 minutes.
  so second time at 6 minutes.
• 11 years agoHelpfull: Yes(18) No(8)
• 120sec--> 1 round, 1sec-->1/120 round, similarly in 1 hr-->30 rounds
  another one covers 1hr-->40 rounds
  hence their relative speed will be-->10 rounds/hr
  1 round will be cover in 60/10 min=6 min
  so they will meet first in 6 sec and second time in 12 min..:-)
• 11 years agoHelpfull: Yes(6) No(0)
• @sruthi how did u got .6x in a minute :/
  i think answer is 12min
  ->man takes 2min to complete a round
  -> bull takes 40 rounds to in = 60min
  so bull takes 1 round in 60/40min=1.5min
  lcm of 1.5 and 2 is 6
  so first MEET(not round) in 6min and 2nd in 12min :)
• 11 years agoHelpfull: Yes(3) No(4)
• As the question says when they'll meet at the starting point second time,therefore answer will be 12 minutes......
  LCM of 120 sec and 90 sec for the first time and double it for the next....
• 11 years agoHelpfull: Yes(3) No(0)
• @sruthi
  if lcm of 2,1.5 is 3 acc. to u than hw can 3 be divided by 2 ?
  there r not so much rounds..make a figure of circle and u will get to know that they will not meet in 3 min..in 3 min, bull will be on start point and man at opposite sde of circumference..
  @divya
  bull takes 40 rounds in = 60min (given)
  so 1 round will be in = (60/40)*1=1/5 (not 40/60 which sruthi did) :)
• 11 years agoHelpfull: Yes(3) No(1)
• @palash but as u did LCM of 1.5 and 2 is 3 !!!! so 2nd time they would meet at 6th minute!!! and i said it covers o.6x distance of total trackin one minute, not o.6 minutes to cover complete track
• 11 years agoHelpfull: Yes(2) No(2)
• @palash bull takes 1 round in 40/60 min= .6.
  so ans. should be 3 min.
  first time they met when they left the starting point
  n 2nd time they will meet again at 3 min.
• 11 years agoHelpfull: Yes(1) No(2)
• magic takes 2min to complete a round and bull takes 40 rounds in 60min
  so bull takes 1 round in 60/40min=1.5min
  lcm of 1.5 and 2 is 6
  so first round in 6min and 2nd in 12min
• 11 years agoHelpfull: Yes(1) No(0)
• in 2mins the man covers 1 round (suppose x m)
  so, in 1 min man covers x/2 m
  
  in 60 mins bull covers 40x m
  in 1 min bull covers 40x/60 m = 2x/3 m
  
  so relative speed of man and bull = (2x/3-x/2)= x/6 m/min
  so while covering x m (i.e in 1 round) bull and man meets after 6 min
  in 2nd round they'll meet after 12 mins
• 11 years agoHelpfull: Yes(0) No(0)
• man 1 round =120sec
  bull 40 rounds in 1 hr so 60/40=1.5=110sec
  lcm of 120,110=1320 sec=1320/60=22min
  for 2nd round 44 min
• 10 years agoHelpfull: Yes(0) No(0)
• @Sruthi The LCM of 2 and 1.5 is not 3. Probably you did take out out the LCM as (2 and 3/2) which is the wrong way to do it.
  
  LCM of fractions is taken out as: 2.0 and 1.5
  20= 2^2 x 5
  15= 3 x 5
  LCM= 4 x 3 x 5 = 60 ~6.0
  Therefore as @Palash did, they would meet at the second round in 12 minutes.
• 10 years agoHelpfull: Yes(0) No(0)
• As the question says when they'll meet at the starting point second time,therefore answer will be 12 minutes......
  LCM of 120 sec and 90 sec for the first time and double it for the next....
• 10 years agoHelpfull: Yes(0) No(0)
• Racing magic takes 120sec per 1 round,
  => 2min per 1 round.
  charging bull takes 1hr per 40 rounds,
  => 60 min per 40 rounds,
  => (60/40) min per 1 round,
  => 1.5 min per 1 round.
  therefore, Racing magic can reach the starting point in 2min, 4min, 6min, 8min, 10min, 12min, 14min,. . . .
  charging bull can reach the starting point in 1.5min, 3min, 4.5min, 6min, 7.5, 9min, 10.5min, 12min, . . . .
  so they meet the starting point for the second time in 12min.
  
• 8 years agoHelpfull: Yes(0) No(0)