A person travels at 30 kmph reaches his office 10 mins late by traveling with a speed of 40 kmph he reaches his ofiice 5 mins early.find out the distance between his home and office

• If he's in the speed of 30 km/h he reaches 10 mins late and if he's in the speed of 40 km/h then he reaches 5 mins earlier. So. there's a time gap of 15 mins in arrival times.
  
  This can be solved through a simple formula,
  
  Required Distance = Product of the speeds/Difference of the speeds * Difference of time gap in arrival
  
  Distance = 40 * 30/40 - 30 * 15/60
  
  = 30 km
  
  Therefore the distance between the home and office is 30 km.
  
  
  ANOTHER METHOD :
  
  Let the distance be x km.
  Time taken to cover x km at 30 km/h = x/30 hrs
  Time taken to cover x km at 40 km/h = x/40 hrs
  
  Difference between the time taken = 15 min = 1/4 hrs
  
  Therefore, x/30 - x/40 = 1/4 => x = 30
  
  So, the required distance is 30 km.
  
• 10 years agoHelpfull: Yes(5) No(0)
• Let the distance b/w his home and office be x
  while travelling at 30kmph he reaches 10min late:-
  speed=distance/time
  30=x/t+(10/60)
  6x-180t=30 - (1)
  Travelling at a speed of 40kmph reaches 5 min Early
  40=x/t+(1/12)
  12x-480t=-40 - (2)
  on solving equation (1) and (2)..
  we get t=10/20
  and x=30
  so distance is 30km
  
• 10 years agoHelpfull: Yes(1) No(0)
• 30(t+0.16)=40(t-0.08) by solving we get t=0.8
  distance=30*0.96=28.8 kms
• 10 years agoHelpfull: Yes(0) No(2)