At a restaurant, customers can choose up to four side dishes and up to two main courses. If a customer must have at least 1 side dish and 1 main course, how many distinct dinner plate combinations are possible?
The answer is 45. I can only calculate 12.
Call the four side dishes A,B,C,D. Call the Main courses E and F.
E goes with A,B,C,D. F goes with A,B,C,D.
Now EF goes with A,B,C,D.