Question

There are five seniors in a class. For each situation, write how the binomial formula is used to calculate the probability.

a) In how many ways can I choose one senior to represent the group?
b) In how many ways can I choose two seniors to represent the group?
c) In how many ways can I choose three seniors to represent the group?
d) In how many ways can I choose four seniors to represent the group?
e) In how many ways can I choose five seniors to represent the group?

I don't need the answer, just an explanation. How can I use the binomial formula to solve this?

Answer 1

n choose k is
\[\left(\begin{matrix}n \\ k\end{matrix}\right)\]

Answer 2

This is the binomial coefficient.
So if you choose 1 senior out of 5 than n=1, k=5
If you choose lets say 4 out of 5 than n=4,k=5