If a train runs at 40 km/h, it reaches the destination late by 11 mins. But if it runs at 50 km/h, it is late by 5 mins only. The correct time for the train to complete its journey is ?
a) 15 mins b) 21 mins c) 13 mins d) 19 mins.

• @ ALL :
  
  EXTREMELY SORRY FOR A VERY IDIOTIC SILLY MISTAKE I'VE MADE IN MY POSTED SOLUTION :
  
  At the last step :
  
  we have got
  
  x = (44-25)=19..
  
  [but in my previously posted solution I have miscalculated the subtraction and
  produced a stupid result = 21]
  
  So, 19 minutes are taken..
  
  So , the CORRECT ANSWER IS OPTION : d) 19 mins.
  
• 12 years agoHelpfull: Yes(12) No(0)
• Let the correct time taken by the train to complete its journey be t mins.
  Then, the given situation can be representedas:
  Speed (km per hour) 40 50
  Time (min) (t + 11) (t + 5) Respectively.
  
  It can be seen that, increase in the speed decreases the time taken.
  Therefore, the two quantities are inversely proportional.
  40(t + 11) = 50(t + 5)
  40t + 440 = 50t + 250
  50t – 40t = 440 – 250
  10t = 190
  t = 19
  Thus, the correct time for the train to complete its journey is 19 mins.
• 12 years agoHelpfull: Yes(9) No(2)
• let x min. is the correct time taken.
  d km is the
  x+11= d/(40/60)........[EQN(1)]
  x+5=d/(50/60)..........[EQN(2)]
  Now,
  {[EQN(1)]/[EQN(2)] } gives,
  (x+11)/(x+5) = (50/60)/(40/60)
  =>(x+11)/(x+5) = (5/4)
  =>4x + 44 = 5x +25
  => x = (44-25)=21
  
  So, 21 minutes are taken.
  
  Correct Answer is OPTION b)21 mins
• 12 years agoHelpfull: Yes(6) No(5)
• Let the distance travelled by the train is x kms.
  Then, x/40*1000/60 - x/50*1000/60 = 60
  
  => 60x /40000 - 60x/50000 = 6
  => 60/10000(x/4-x/5) = 6/1
  => x/20=1000
  => x = 20 km
  
  Thus correct time = 20/40 * 60 - 11
  = 30 - 11
  = 19 mins.
  
  Anyone has a simpler solution ? Help me out
• 12 years agoHelpfull: Yes(3) No(3)
• ANS: d) 19 mins
  Solution:
  s=D/T
  1. 40=D/(x+11)
  2. 50=D/(x+5)
  from 1
  40x+440=D
  from 2
  50x+250=D
  By solving this two equations, we get x=19 mins
  
• 12 years agoHelpfull: Yes(3) No(1)
• ans. 19 mins...
  soln:
  let x is time taken.
  x+11= d/50
  x+5=d/40
  solving these eqn, we get x=19
• 12 years agoHelpfull: Yes(1) No(2)
• if the correct time is x, then....
  (x+11)*40=(x+5)*50
  =>4x+44=5x+25
  =>x=19
  so,the ans will be 19mins.
• 12 years agoHelpfull: Yes(1) No(0)
• ans. 21 mins...
  soln:
  let x is time taken.
  x+11= d/50
  x+5=d/40
  solving these eqn, we get x=21...
• 12 years agoHelpfull: Yes(0) No(5)
• x=40(t-11).....eq(1)
  x=50(t-5)......eq(2)
  eq(1)=eq(2)
  than,t=19
  ans(D)
  by vikash saini
• 12 years agoHelpfull: Yes(0) No(0)
• let x is time taken.
  x+11= d/50
  x+5=d/40
  solving these eqn, we get x=19
  
• 10 years agoHelpfull: Yes(0) No(0)
• 40(t+11)=50(t+5)
  t=19 min
• 6 years agoHelpfull: Yes(0) No(0)