My friend Charles works in a post office and he sells stamps. One day a man walked in and slamming seventy five rupees on the counter requested,
"Please give me some 2 rupees stamps, six times as many one rupee stamps, and for the rest of the amount make up some 5 rupee
stamps."
Charles thought for a few moments and finally she handed over the exact fulfilment of the order to the man.
How did he do it and how many stamps of each type did he give to the man ?
x=number of 2 rupee stamps
6x=number of 1 rupee stamps
y=number of 5 rupee stamps
2x+6x+5y=75
8x+5y=75
8x must be divisible by 5, so x is divisible by 5. If x=10, then 8x=80, which is greater than 75. Therefore, x=5. Also, 6x=30, so there are 30 1 rupee stamps.
40+5y=75
5y=35
y=7
5 2 rupee stamps
30 1 rupee stamps
7 5 rupee stamps

Posted by Math Man
on 20110710 11:48:43 