Carmen got a prepaid debit card with $15 on it. For her first purchase with the card, she bought some bulk ribbon at a craft store. The price of the ribbon was 13 cents per yard. If after that purchase there was $12.79 left on the card, how many yards of ribbon did Carmen buy?

We can start by finding how much money Carmen spent on the ribbon:

$15 (initial balance) - $12.79 (remaining balance) = $2.21 spent on the ribbon

Now we can use the price per yard to find how many yards Carmen bought:

$2.21 ÷ $0.13 per yard = 17 yards

So Carmen bought 17 yards of ribbon with her prepaid debit card.