Q:

multiple selection drop down list

I would like to count the number of unique selections from a column that contains multiple selections from a drop down list.
For example, column B3 contains,

Monday, Tuesday, Wednesday

The count function returns a value of 1 instead of 3 - is there any way to count the three days distinctly? Thank you!
Multiple selections from a drop down list was made possible using the VBA code from: https://docs.google.com/document/d/1JU7G_Tna2zPBtcG2TlarxKCTbuinNsg5LwBqzmuJYK8/edit

A:

This solution is contingent on your string values always being separated by a comma (,). It appears that the code you shared in the link will continue to add comas with the addition of each new string, which means this should work for you.

=IF(A1="",0,LEN(TRIM(A1))-LEN(SUBSTITUTE(TRIM(A1),",",""))+1)

If cell is  blank, return 0 
Else, Count instances of commas (,) and offset by 1

Edit 1: (Explanation)

Notice the equation has two very similar parts: LEN(TRIM(A1)) & LEN(SUBSTITUTE(TRIM(A1),",","")). The only difference is that one equation uses the Substitute function and the other does not. 
Trim will remove leading and lagging spaces
Len returns the character count of your string
Substitute, in this instance, is used to replace (substitute) all commas with a blank string ("")  
The difference between the length of the string with commas to the length of the string without commas equals the total commas that are present in the string. Saying to "count the commas" was a little misleading on my part since we are really deducing the number of commas. 

