Respuesta :
Answer: 3 Sets of the 4 post cards and 3 of the single post cart sets.
Step-by-step explanation:
You buy 3 of the 4 post card set becuase that is the most you can get of those to get under 15 post cards.
You would now have 12 postcards now you have to buy 3 of the single set to get to 15 cards
You would buy the set of four postcards 4 times. This would equal $4 for 12 postcards. Then you would have to buy 3 individual postcards. Those 3 postcards would be $1.50
$4+$1.50=$5.50
$4+$1.50=$5.50
