Answer:
Kaitlin bought 48 yards of ribbon.
Explanation:
Hey! Let's help you with your question here!
So, let's start by figuring out what we know and what we need to figure out. First of all, we started with $15 and ended with $4.92. We also know that the price of the ribbon is $0.21 per yard and we need to figure out how many yards of ribbon she purchased.
In order to figure this out, we first want to know the difference in the price between what we started and what we ended up with. So, we can subtract! It would look like this:
So, we figured out that the difference in the price is $10.08, but how do we find out how many yards of ribbon Kaitlin bought? Well, since we know that it is $0.21 cents for a yard of ribbon, we can just take the difference in price and divide it by how much a ribbon cost for a yard of it. So it would look like this:
We have a nice whole number and that's our answer! Therefore, Kaitlin bought 48 yards of ribbon.
Mathematical Way:
To do it in a more mathematical way, we can put it in the form of a formula. We know that the end total is $4.92 and the initial is $15. We also know that it's $0.21 cents per yard of ribbon but we don't know how many yards she bought. We can let the number of yards she bought represent x in the formula, so we have:
This formula makes sense because we start with $15 at the beginning, so we want to add $4.92 from 0.21x because the end total is the remainder of how many yards Kaitlin bought. The process is essentially the same as the method above. If we were to solve the formula, it would give us the same answer:
- Moving the 4.92 over to the left side, beginning to isolate x.
- Subtracting $4.92 from $15.
- We divide by $0.21 to solve for x.
And here, we get the exact same answer, 48 yards of ribbon.