An Office used three types of envelopes: small,medium and large. They used 80 small envelopes. The no.of Medium envelopes used was 5 times, the no.of small envelopes plus 5/20 of the number of envelopes. The no.of.large envelopes was equals to the no.of small envelopes plus 5/20 of the no.of medium envelope. Altogether, How many envelope did they use?

• 960
  
  Let the total no. of envelopes be x
  
  No. of small envelopes = 80
  No. of medium envelopes =5*80+5/20*x = 400+5/20*x
  No. of large envelopes = 80 +5/20(400+5/20*x) = 180+25/400*x
  
  Sum of small, medium and large envelopes = x
  
  80 + 400+5/20*x + 180+25/400*x = x
  660 + 5/16*x = x
  11/16*x = 660
  x = 960
  
• 10 years agoHelpfull: Yes(7) No(0)
• sry its 16*60=960 envelopes.......
• 10 years agoHelpfull: Yes(3) No(0)
• medium envolopes = 80*5 + 5/20x =400 + 5/20 x
  large envelopes = 80+5/20(400 +5/20 x)
  total envelopes =80 + 400 + 1/4 x +80 +100 +1/16 x = x
  660+5/16 x = x
  11/16 x = 660
  x = 6*60 = 360......
• 10 years agoHelpfull: Yes(0) No(3)