23 envelopes cost Rs 57.50. How many envelopes can be bought for Rs 127.50.
(a) 55
(b) 56
(c) 51
(d) 53

• if no of envelopes increase, cost will increase so it is a direct proportion
  envelope cost
  23 57.50
  x 127.50
  
  23/x=57.50/127.50
  x=23*127.50/57.50
  x=51
• 11 years agoHelpfull: Yes(4) No(0)
• 51 is the answer...
  1 envelop cost is 2.5 by dividing 57.5/23 we get 2.5,
  hence 127.5/2.5=51
• 6 years agoHelpfull: Yes(0) No(0)