Question

A coffee shop needs to purchase custom cups. Company C charges a flat fee of $155 plus $15 perrl cup. Company D does not have a flat fee but charges $30 per cup.

What is the minimum number of cups that must be ordered for company C to be a better deal than company D?​

Answer 1

11 cups

Explanation:

Not really a method just started at 10 and then realised deal d was better so go up by one so 11 and c worked out better as I timed 30 by 11 and 15 by 1 + the flat fee.