You can
put this solution on YOUR website!Let x=no of 3 cent stamps
3x-1=no of 8 cent stamps
(3x-1)-6=no of 15 cent stamps or 3x-7
3x+(3x-1)*8+(3x-7)*15=247
Simplifying we get:
3x+24x-8+45x-105=247
72x-113=247
Adding 113 on both sides, we get:
72x=360
Dividing both sides by 72 we get
x=5
So there are:
5 3-cent stamps
14 8-cent stamps
8 15-cent stamps