Fate has decided that this Friday night will be spent at a party. After three cups of punch from a bowl of unknown origin, Sam and Dean attempt to court the same lovely lady. Dean goes first and has an 80% chance of making the girl roll her eyes, while Sam has a 15% chance (independent of the actions of Dean) of doing the same. What is the chance that she will roll her eyes for only one of them before the night has ended?
You don't have to tell me the answer, just telling me how to set up this problem is enough!
You don't have to tell me the answer, just telling me how to set up this problem is enough!