Galaxy express leaves Pune at 8:00 AM and reaches Mumbai at 1:00 PM same day and Croma express leaves Mumbai at 10:00 AM and reaches Pune at 1:00 PM same day. At what time do the two trains cross each other?

• A travels 5hrs and B travels 3 hrs let the arbitrary distance be their lcm i.e 15km so A travels 3km/hr and B travels 5km/hr. Now A covers 6kms in 2hrs and after that the remaining distance is 9km so both of them meet after 9/(5+3) =1.125 hrs after 10
• 7 years agoHelpfull: Yes(22) No(3)
• Let the distance be 15k(LCM of 5 and 3 i.e. time taken by both the trains). Speed of galaxy = 15k/5= 3k and speed of croma= 15k/3=5k. Now distance travelled by galaxy from 8:00 AM to 10:00 AM= 3k*2=6k.
  Now let t be the time after 10:00 AM when both the trains meet:
  => 3k*t+5k*t=(15k-6k)
  => 8kt=9k
  => t=9/8 hrs
  => 1 hr 7 mins and 30 sec.
• 7 years agoHelpfull: Yes(6) No(1)
• when total distance is not given to us then, just take the LCM of time taken by both the trains.
  Given-
  time taken by galaxy express from pune to mumbai is 5 hrs.
  
  time taken by croma express from mumbai to pune is 3 hrs.
  
  Now, Take the LCM of 5 and 3 which is 15.
  
  Now, calculate the speed of galaxy express = 15/5 = 3 km/h
  Now, calculate the speed of croma express = 15/3 = 5 km/h
  
  At what time they will meet/cross each other. So, to calculate this apply formula = Total distance/relative speed.
  but before apply this one thing is to keep in mind that the STARTING TIME of both the train should be same for finding their meeting time.So, galaxy express will travel 6km in two hours means upto 10AM galaxy express completes 6km of journey out of 15 km. therefor, remaing distance is 9km left.So, now our total distance is 9km.
  
  Apply formula--
  9/8 gives us 1*1/8 hour. convert 1/8 into minutes which is (1/8)*60 = 7.5
  So. they will meet after 1 hour 7 minutes 30 sec.
  So, the answer is 11:07:30 AM
• 6 years agoHelpfull: Yes(4) No(0)
• Calculating time after the start of Croma express, as the other solutions states, we get time = 1.125 hrs.
  Adding that to the 3 hr travelled by Galaxy express time, we get = 3.125 hrs
  This expands to 3 hours 7 minutes 30 seconds.
  
  So 8 AM is 8:00:00 + 03:07:30 = 11:07:30 AM
• 7 years agoHelpfull: Yes(3) No(0)
• 1.125+2 total 3.125 hr
• 7 years agoHelpfull: Yes(2) No(0)
• let total distance be "D" and let train cross each other after time "t"
  let croma express covers x distance in time t
  v(galaxy)=D/5 and V(croma)=D/3....(1)
  v(galaxy)=(D-x)/t and v(croma)=x/t
  so D/3=x/3 (using 1)
  and (D-x)/t=D/5.....(2)
  => D/t -x/t=D/5
  =>D/t-D/3=D/5
  =>1/t- 1/3=1/5
  =>t=15/8hr after 10 am
  i.e.. 1hr 52 min 30 sec
  so required answer is 11:52:30 am
• 7 years agoHelpfull: Yes(1) No(2)
• Either distance between two cities or speeds of the trains must be known to get the the answer.
• 7 years agoHelpfull: Yes(0) No(12)
• let the distance between pune and mumbai is x
  now speed of galaxy express is x/5.....(8am to 1 pm= 5 hr)
  speed of croma express is x/3....as(10am to 1 pm=3 hr)
  now galaxy exp travel total distance till 10 am = (x/5)*2=2x/5
  remaining distance=x-2x/5=3x/5
  now suppose both the train cross each other after t time
  so we can write:
  (x/5)*t+(x/3)*t=3x/5
  after solving this we got t=3/2
  so total time = 2+3/2= 7/2=3.5 hr
• 7 years agoHelpfull: Yes(0) No(8)
• Lets take a random distance which is divisible by both i.e., 15KM (T1 = 3KM/H and T2 = 5KM/H).
  T1 covers 6km in 2 hrs and T2 covers 10km. so time should be less than 2 hrs.
• 7 years agoHelpfull: Yes(0) No(0)
• Speed of the train, Galaxy express Pune: P=PM/5, with PM the distance Pune-Mumbai.
  
  Speed of the train, Croma express Pune: M=PM/3, with PM the distance Pune-Mumbai.
  
  Train, leaving Pune at 8:00 AM, travels a distance PM/4 ,in 2 hr 10.00 am.
  
  At that time, both trains travel a distance PM/2 = P.t+ M.t = PM/5.t + PM/3.t.
  
  Calculating: t = 15 minutes. Time of crossing: 10.00 + 0.15.
  
  the two trains cross each other=10.15 AM
• 7 years agoHelpfull: Yes(0) No(1)
• a simple formula for this type of problems =
  
  PUNE to MUMBAI , it took 5 hrs in total [ T1 ]
  MUMBAI to PUNE , it took 3 hrs in total [ T2 ]
  also galaxy express start time at pune ( 8am ) and croma express start time at mumbai (10am )
  ( time gap ): 2 hours .
  So the formula is cross time T = ( T1 - time gap ) x ( T2 / T1 + T2 )
  The answer you'll get on substituting those values is 9/8 hrs i.e 1.125 hrs .
• 5 years agoHelpfull: Yes(0) No(0)