there are two trains A and B ,A starts from mumbai at 10am @ 51kmph towardsdelhi and B start from Delhi to Mumbai @ 50kmph at 11am
distance between them is 273km and each min of time when both comes towards each other B counts the distance so how many times B calculates distance as whole number.

• ans: 2 times
  speed of train A=51kmph
  speed of train B=50kmph
  distance between trains=273km
  train B starts after 1 hr , at that time train A has already covered 51 km
  i.e. remaining distance between train=273-51=222km
  relative speed of train=51+50=101kmpr
  in min =101/60kmpm
  101 is a prime number.
  time taken by trains to cover the distance 222km=222/101= approx 2hr20 min
  that means after every 60 min the driver will get a whole number
  therefore he will get whole number only 2 times.
• 9 years agoHelpfull: Yes(29) No(1)
• relative spd=101km/p,distance left =(273-51)=222 km..
  it will take to cover approx 2.2 hrs.means approx 132 mins. so he counts 132 mins
  
• 9 years agoHelpfull: Yes(4) No(13)
• ans: 2 times
  speed of train A=51kmph
  speed of train B=50kmph
  distance between trains=273km
  train B starts after 1 hr , at that time train A has already covered 51 km
  i.e. remaining distance between train=273-51=222km
  relative speed of train=51+50=101kmpr
  in min =101/60kmpm
  101 is a prime number.
  time taken by trains to cover the distance 222km=222/101= approx 2hr20 min
  that means after every 60 min the driver will get a whole number
  therefore he will get whole number only 2 times.
• 8 years agoHelpfull: Yes(1) No(0)
• Relative speed=90kmhr, distance b/w them @ 1pm is 222km(273-51)..
  Now B calculates distance b/w them in every min so time=222/90 approx time=2.40hr i.e =160min so he counts 160 times.
• 9 years agoHelpfull: Yes(0) No(13)
• distance traveled at 1 pm:
  A=51km and B=0 (count=0)
  at 2 pm:
  A=51km and B=49 (count= 60 )
  at 3 pm:
  A=51 km and B=49(count=60+60)
  Distance remaining till 3 pm=273-(51*3+49*2)=20 km
  at 3:12 pm:
  A=11km(approx) and B=9km(approx) (count=60+60+12)
  so B counts till 3:12 pm=132 times
• 9 years agoHelpfull: Yes(0) No(3)
• distance left =(273-51)=222 km.
  distance travel by both in 1 min=51/60+50/60=101/60=1.6833.
  No. of times B calculates distance=222/1.6833=131.8838.
  means B will count 131 times.
  
• 9 years agoHelpfull: Yes(0) No(0)
• distance left =(273-51)=222 km.
  distance travel by both in 1 min=51/60+50/60=101/60=1.6833.
  No. of times B calculates distance=222/1.6833=131.8838.
  means B will count 131 times.
  
• 9 years agoHelpfull: Yes(0) No(0)
• Ans:- 1 Time
  
  speed of train A=51kmph
  speed of train B=50kmph
  distance between trains=273km
  train B starts after 1 hr , at that time train A has already covered 51 km
  i.e. remaining distance between train=273-51=222km
  relative speed of train=51+50=101kmph
  time taken by trains to cover the distance 222km=222/101= approx 2hr20 min or 131 min Apprx.
  
  101/60=1.68km/min. or 222/131=1.68km/min
  
  when B count distance at 100th min then the total distance remaining is :-
  222-(1.68*100)=54km.
• 5 years agoHelpfull: Yes(0) No(0)