I found a problem while solving this -
Three friends will eat sweets. One can eat only one sweet of one type, or no sweet at all. They are allowed to choose from three different types. In how many different ways can they eat sweets?
My question is - If all of them deny to eat sweets, how many ways will be there? 0 (i.e. No way to eat sweets) or 1 (i.e. all of them deny to eat)?