Question

A hot dog stand sells hot dogs with cheese, relish, chili, tomato, onion, mustard, or ketchup. How many different hot dogs can be concocted using any 5 of the extras?

Answer 1

You can obtain your answer by using a scientific calculator in order to get the nCr of the problem above. Since you have seven choices and they use 5 in extras.
Using the calculator, you have to solve by: 7 nCr 5
The nCr is a function in the calculator that will help you obtain your answer.
The answer of that would be 21.