In how many different ways can a person select one book from 3 novels, one book from 5 biographies and one book from 7 self-help books? a). 15

b). 105

c). 3

d). 22

And that's equivalent to:

Where C represent the term combinatory defined as:

And then the number of ways to select the three books are 105, and the best option would be:

b). 105

Step-by-step explanation:

For this case we can use the multplication principle of counting or sometimes called the product rule.

We have a total of 3 novels, 5 biographies and 7 self-help books. And we can find the number of ways that a person can select the three books with theis product:

And that's equivalent to:

Where C represent the term combinatory defined as:

And then the number of ways to select the three books are 105, and the best option would be:

b). 105

(x) - (y) = (1 + 4i)