Respuesta :
Answer:
The number of different combinations that are possible are:
495
Step-by-step explanation:
The method of combination states that:
If we have to choose r items out of a total of n items then the number of ways of doing so is calculated by the formula:
[tex]n_C_r=\dfrac{n!}{r!\times (n-r)!}[/tex]
Here we are asked to find:
The number of combinations possible when we have to choose 4 books out of 12 books.
i.e. we have: n=12 and r=4
Hence, the number of ways is calculated as follows:
[tex]{12}_C_4=\dfrac{12!}{4!\times (12-4)!}\\\\\\{12}_C_4=\dfrac{12!}{4!\times 8!}\\\\\\{12}_C_4=495[/tex]
