Question

Roxie is picking out some movies to rent, and she is primarily interested in horror films and documentaries. She has narrowed down her selections to 66 horror films and 1515 documentaries. Step 2 of 2 : How many different combinations of 33 movies can she rent if she wants at least two documentaries?

Answer 1

1,085

Explanation:

The calculation of number of different combinations of 3 films she can rent if she needs at least two documentaries is shown below:-

`= N* (2 * documentaries\ and\ 1\ horror \ movies)+N* (3\ documentaries)`

`=(6C_1)* (15C_2)+(6C_0)* (15C_3)`

= 630 + 455

= 1,085

Therefore for calculating the number of different combinations of 3 films she can rent if she needs at least two documentaries we simply applied the above formula and here we consider one number in the question as it shows the double number.