If a certain computer is capable of printing 4700 monthly credit card bills per hour, while a new model is capable of printing at a rate of 6800 per hour, the old model will take approximately how much longer than the new model to print 10000 bills?

• old model's 1 hr work = 4700
  new model's 1 hr work = 6800
  old model' time taken to print 10000 cards
  for 1 hr -- 4700 cards
  x -- 10000
  x= 10000/4700 = 100/47
  
  new model' time taken to print 10000 cards
  for 1 hr -- 6800 cards
  y -- 10000
  y= 10000/6800 = 100/68
  x= 10000/4700 = 100/47 = 2 6/47 hr
  
  Difference is
  100/47 - 100/68 = 6800 - 4700 /(47*68)
  
  2100/3196 = 0.66 hrs => 39minutes
  
  Old model ll take 39 minutes longer to print 10000 cards than new model
  
  Ans : 39 mins
• 10 years agoHelpfull: Yes(18) No(0)
• old machine takes 1 hour to print 4700 cards
  new machine takes 1 hour to print 6800 card
  for old ,if the cards are 10,000 than time taken by it will be = 10000/4700 = 100/47hr
  similarly for new machine it takes time = 100/68hr
  difference = 100/47-100/68 = .66 hr = 39 min.
• 6 years agoHelpfull: Yes(0) No(0)