Answer: It costs $5.52 to Sam to buy 12 stamps.
Step-by-step explanation:
Given: Sam paid $8.28 for 18 stamps.
Thus, the cost of 18 stamps = $8.28
Then the cost of 1 stamp=[tex]\frac{8.28}{18}[/tex]
Thus, the cost of 1 stamp=$0.46
With the same rate , the cost of 12 stamps=[tex]0.46\times12[/tex]
Therefore, the cost of 12 stamps= $5.52
hence, it costs $5.52 to Sam to buy 12 stamps.
