We want to find how many different combinations (each outfit is a combination of clothes) of clothes Lucy has. We will see that she can wear different outfits for 165 days.
The first thing we need to identify is the selections, here we have 3:
Now we must find the number of options for each one of these selections:
The total number of combinations is just the product between the numbers of options, this gives:
C = 8*7*3 = 168
Now we know that a dress and a pair of shoes can't go together, then we need to remove 3 of the above combinations (one for each pair of earrings)
So we have:
168 - 3 = 165
This means that she can wear different outfits for 165 days.
If you want to learn more about combinations, you can read:
https://brainly.com/question/3732964