MathProbability
posted by jj on .
A deli offers its cheese sandwich with various combinations of mayonnaise, lettuce, tomatoes, pickles, and sprouts. 8 types of cheese are available. How many different cheese sandwiches are possible?

Assuming you can have one and only one type of cheeze (i.e., no provolone and swiss sandwiches allowed), and assuming you cannot get extra toppings (e.g, no sandwich with extra mayo allowed)....
There are 8 type of cheese and 5 toppings. With each topping, there are 2 possible answers, either yes or no.
So 8*(2^5) = 256. 
Thank you, that helped out a lot!