Let's try to get something that would work for just 5 for now. Any of these numbers would leave a remainder of 1 when divided by just 5: 6, 11, 16, 21, 26, 31, 36, 41, 46, 51, 56, 61, 66, 71, 76, 81, 86, ... Notice that they all look like 5*(something) + 1. Basically, they are all multiples of 5 plus 1.
Let's see what would work for just 8: 9, 17, 25, 33, 41, 49, 57, 65, 73, 81, 89, ...
Are there any matches... AHA! It's 81. This is the lowest positive integer greater than 1 that follows the rule for both 5 and 8.
States that if there are p ways to do a thing, and q ways to do another thing, and these two things are independent, there are p*q ways to do both things.
In this question:
4 types of drinks
5 types of sandwiches.
3 types of chips.
They are independent events, so, by the fundamental counting principle:
The value on n is simply the number of values or the size of the sample data. In our case, we have a total of 8 data values. The value of n will thus be 8
