Question

Brad paid for a book that cost $13.40 with a $20 bill. What is the least combination of coins and bills that can be used to make his change? What are two other different combinations of coins and bills that can be used to make the change?

Answer 1

First combination: One $5 bill, one $1 bill, two quarters and one dime.

Second combination: One $5 bill, one $1 bill, two quarters and two nickles.

Explanation:

I highly suggest reading it to make sure you understand it

Okay so for this one you're going to want to do 20.00-13.40. The answer to that is 6.60

So we have to work with $6.60

Now lets think of the obvious/easiest.

A $5 bill is going to be our best friend in this.

We have to do

6.60-5.00=x

(Don't freak out about x, it's just our place marker!!)

The reason we do 5.00 is because that's what $5 is.

So let's solve now.

6.60-5.00=1.60

So x=1.60

But you don't have to worry about x, I'm just explaining it from before.

So we have to keep in mind that we used one $5 bill. Now let's use one $1 dollar bill.

1.60-1.00=0.60

So now we only have to figure out how to get 60 cents from any of the coins.

A quarter is 25 cents so lets use two of those

25+25=50

60=50=10

Lets recap on everything we've used so far.

We've used one $5 bill, one $1 bill, and two quarters.

Now we're going to add a dime to the mix.

A dime is worth 10 cents.

So for the first combination we used: One $5 bill, one $1 bill, two quarters and one dime.

Now our second combination is going to be really easy.

We can use almost everything the exact same, we're only going to switch up the dime part.

1 dime = 2 nickles

Nickles are worth 5 cents

So we take out the dime and replace it with two nickles.

So for the second combination we use: One $5 bill, one $1 bill, two quarters and two nickles.