The difference between the time taken by two cars to travel a distance of 350 km is 2 hours 20 minutes. If the difference between their speeds is 5 km/hr., what is the speed of faster car in km/hr.?
a) 30
b) 35
c) 40
d) 45
e) 50

• 350/s-350/(s+5)=7/3
  s=25,-30
  we consider initial speed s,s+5
  25,25+5=30
• 8 years agoHelpfull: Yes(7) No(0)
• Let Time taken by faster car = t
  Time taken by slower car = t + (2 + 20/60) = t + (7/3)
  Difference of speed = 5
  350/t - (350/ (t + 7/3) = 5
  350/t - 1150/(3t + 7) = 5
  (1150t + 350 *7 - 1150t) /(t * (3t + 7)) = 5
  5 * (3t^2 + 7t) = 350 *7
  3t^2 + 7t = 490
  3t^2 +7t - 490 = 0
  3t^2 + 42t - 35t - 490 = 0
  On solving, we get
  t = - 14 and 35/3
  But time cannot be negative, so we will take positive value.
  Speed of the faster car,
  = Distance traveled / time taken
  = 350/(35/3) = 30 kmph.
• 6 years agoHelpfull: Yes(0) No(0)