#### Explanation:

So since she is buying three boxes of popcorn, you multiply it by the price of the popcorn as shown below:

$1.95 \cdot 3 = 5.85$

You subtract the amount she given to the person then the cost of three popcorn as shown below:

$10.00 - 5.85 = 4.15$

So she receives \$4.15 in change.