A car goes from A to B with certain velocity.Due to some problem in the engine after travelling 30 km,it goes in 4/5th of actual velocity and reach B 45 minutes late.If engine fails after 45km,then reach B 36 minutes late.Find velocity and distance between A and B.

• the answer is
  initial velocity is 25 km/hr
  and distance is 105 km
  explanation
  let distance = xKm and Velocity = yKm/hr
  form 2 equations
  total time = time from start to first break point+ time
  from first breakpoint to destination
  (time = distance/speed)
  total time fromassumption = (x/y)
  for first case
  total time = (x/y)+(3/4){36 minutes converted into hrs}
  time from start to first break point = (30/y)
  time from first break point to destination = (x-30/(4/5y))
  {since velocity has decreased to 4/5}
  hence
  x/y + 3/4 = 30/y + (x-30/(4/5y)) .......... equatiion 1
  similarly equation 2 is derived from 2nd case given as:
  x/y + 3/5 = 45/y + (x-45/(4/5y)) .......... equatiion 2
  solving v get x=105
  and y = 25
  its seems to be lengthy in reading the solution but trust
  me it wont take more than 2 mins to solve the question
• 10 years agoHelpfull: Yes(7) No(0)
• let the total distance=x
  
  the difference in time is 45 m =3/4 hr
  
  30/v+(x-30)5/4v-x/v=3/4........................1
  45/v+(x-45)5/4v-x/v=3/5.........................2
  
  after euating 1 and 2
  
  5x-12v=225
  4x-12v=120
  
  solve
  we get x=105 and v=25
  
• 10 years agoHelpfull: Yes(4) No(0)
• Car gets late 45-36=9min when it covers 45-30=15km by 4/5 of actual velocity
  so it will take 15*5=75km to get late by 9*5=45 min
  so total distance=30+75=105
  
  alternate
  let the total distance =x
  let the velocity = 5y
  
  1. (x-30)/4y - (x-30)/5y = 45/60
  2 (x-45)/4y - (x-45)/5y =36/60
  
  by solving eq 1&2---->x=105, velocity=5y=25
  
  
• 10 years agoHelpfull: Yes(2) No(0)
• velo=25kmph and Dist=105km..
  convert minutes to hour and then simple two equation two variables
• 10 years agoHelpfull: Yes(1) No(3)
• velocity = 25, distance=105
• 10 years agoHelpfull: Yes(0) No(0)