Now suppose that out of the 10 dishes that the restaurant offers, only 3 of them are vegetarian. If Fiona must select a vegetarian option on Friday, how many ways are there for her to select her lunches?

The number of ways she can select her lunches N;

N = 10*10*10*10*3 = 30000 ways

Step-by-step explanation:

Number of week days = 5

Total number of dishes = 10

Number of vegetarian dishes = 3

Note; on other week days apart from Friday she can select any lunch she want vegetarian or not ...

Therefore, on Monday to Thursday she has ten choices per day, and on Friday she has 3 choices

The number of ways she can select her lunches N;

N = 10*10*10*10*3 = 30000 ways