6.6k views
3 votes
How many sets of four books to read can be chosen from a set of 13 books

User KMFR
by
9.0k points

1 Answer

3 votes

Final answer:

To determine the number of sets of four books that can be chosen from a set of 13 books, use the concept of combinations. The formula to calculate combinations is C(n, r) = n! / (r!(n-r)!), where n is the total number of objects and r is the number of objects to choose. In this case, C(13, 4) = 715.

Step-by-step explanation:

To determine how many sets of four books can be chosen from a set of 13 books, we can use the concept of combinations. The number of combinations of choosing r objects from a set of n objects is given by the formula: C(n, r) = n! / (r!(n-r)!). In this case, we want to choose 4 books from a set of 13 books, so the formula becomes C(13, 4) = 13! / (4!(13-4)!). Simplifying this expression gives us: C(13, 4) = 13! / (4!9!).

Now, we need to calculate the factorial of 13, 4, and 9. The factorial of a number is the product of all positive integers less than or equal to that number. We can use the formula: n! = n * (n-1) * (n-2) * ... * 3 * 2 * 1.

Therefore, C(13, 4) = 13 * 12 * 11 * 10 / (4 * 3 * 2 * 1 * 9 * 8 * 7 * 6 * 5) = 715. So, there are 715 sets of four books that can be chosen from a set of 13 books.

User Madona Wambua
by
7.9k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.