Heather 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 8 cents per yard. If after that purchase there was $11.88 left on the card, how many yards of ribbon did Heather buy?
Heather had $15 - $11.88 = $<<15-11.88=3.12>>3.12 left on the card after buying the ribbon.
She bought $3.12 / $0.08 = <<3.12/0.08=39>>39 yards of ribbon. Answer: \boxed{39}.
To find out how many yards of ribbon Heather bought, we need to calculate the total price of the ribbon first. We know that she spent $15 - $11.88 = $3.12 on the ribbon.
Now, let's figure out how many yards of ribbon this corresponds to. Since the price of ribbon is 8 cents per yard, we can divide the total amount spent by the price per yard: $3.12 / $0.08 = 39.
Therefore, Heather bought 39 yards of ribbon.