Human: Roxanne bought 2 cups of lemonade for $2 each and 2 sandwiches for $2.50 each. How much change must she get from a $20 bill? Assistant:
Two cups of lemonade amount to $2 x 2 = $4.
Two sandwiches amount to $2.50 x 2 = $5.
So, the total amount that Roxanne had to pay was $4 + $5 = $9.
Thus, her change must be $20 - $9 = $11.