The first step is to write each factor in expanding notation.
This is:
- 124 = 100 + 20 + 4
- 2 = 2
Now muliply 2 times each term of the terms 100, 20 and 4
=> 2 * 100 = 200
2 * 20 = 40
2 * 4 = 8
Then,
(100 + 20 + 4 )
x 2
-----------------------
8
40
200
------------------------
248
You would probably need a little larger sample of people because not all people wear corrective lenses. In almost any other survey, this would be a scientist’s dream, but in this one, you’d need it to be a little bigger.
Consider the attached tree.
You start from the root, and with each level you create a sub-branch for each of the choices you have.
So, the root has two children, white and multigrain bread.
Each of those children has three children, because you have three meat choices
Each of those children has two children, because you have two cheese choices.
Then, you identify all the sandwiches by choosing a leaf, and read the label that lead you there.
For example, leaf number 4 represents a sandwich with white bread, turkey and provolone.
First multiply them out to improper fractions 1 3/5 changes into 8/5 and 1 2/5 changes into 7/5 multiply them out and you should get 2 6/25.