2310.21 – Coffee Break
Your boss took everyone for a coffee break. A look at the check told you that she paid $15.75 for three sandwiches, seven cups of coffee, and one piece of pie. Next time, the check was exactly $21 for four sandwiches, ten cups of coffee, and one piece of pie.
If you go by yourself tomorrow and have a sandwich, a cup of coffee, and a piece of pie, what will you pay?
We are told that
where , , and are the prices of individual sandwiches, cups of coffee and pieces of pie. Let's multiply the first equation by 3 and the second equation by 2:
Subtracting the second from the first: