A car completes a certain journey in 8 hours. It covers half the distance at 40 kmph and the rest at 60 kmph the length of the journey of the journey is

• let journey is of x km
  
  time = distance / speed = (d1/s1 + d2/s2)
  => 8 = (x /2)/40 + (x/2)/60
  => 8 = x/80 + x/120
  => x(1/80 +1/120) = 8
  => x*200/80*120 = 8
  => x = 8*80*120/200 = 384 km
• 10 years agoHelpfull: Yes(11) No(0)
• 384 km is the answer
• 10 years agoHelpfull: Yes(1) No(1)
• let journey is of x km
  time= distance/speed
  =>8= { (x/2)/40} + { (x/2)/60}
  =>8={ (x/80) + (x/120) }
  =>8= (3x + 2x)/240 (LCM of 80,120 is 240)
  =>8=(5x/240)
  =>8= x/48
  =>x=384
  ans is 384
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• Let the total journey distance be d.
  First half distance =d/2 covered at 40kmph
  Time taken = d/2 * 1/40 = d/80
  Similarly other half distance at 60kmph
  Time taken = d/2 * 1/60 = d/120
  Thus total time taken d/80 +d/120 ---(1)
  From question ,Total time taken = 8 hours ----- (2)
  
  Equating (1) & (2),
  d/80 +d/120 = 8
  Thus , d = 384 kms.
  Solved.
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