Respuesta :
Using the permutation and the combination formula, we have that:
a) The first three finishers can be awarded medals in 504 ways.
b) They can be arranged in 252 ways.
c) In how many ways can 4 students form a team from a set of 8.
- If the order is important, the permutation formula is used.
- If the order is not important, the combination formula is used.
Combination formula:
[tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by:
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
Permutation formula:
The number of possible permutations of x elements from a set of n elements is given by:
[tex]P_{(n,x)} = \frac{n!}{(n-x)!}[/tex]
Item a:
Order is important, as the finishers are ranked, hence:
[tex]P_{(9,3)} = \frac{9!}{6!} = 504[/tex]
The first three finishers can be awarded medals in 504 ways.
Item b:
The order is not important, hence:
[tex]C_{10,5} = \frac{10!}{5!5!} = 252[/tex]
They can be arranged in 252 ways.
Item c:
Situation in which the order is not important, hence, for example, in how many ways can 4 students form a team from a set of 8.
For more on permutation/combination, you can take a look at https://brainly.com/question/25247153
