<PRE><B>Question 189097</B>
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</PRE>