Since I don't drink coffee, you are unlikely to ask me that question. But if you did, I might assume you are either joking or an idiot ;).

Clearly, it's a trick question (with unnecessary details to distract you from a possible solution) and the one asking probably thinks they are very clever. So now, whether you accept an equation or insist that it's impossible to solve when it's not really comes down to how you want to play that game.