00:01
R has a function to calculate the factorial of a number.
00:05
So for the first question, we just need to compute what is the factorial, because in the question they are saying, like, what is this number? so this number is the factor of 8.
00:17
To compute this using r, you're going to just put like a factorial, everything together, and the number that we want, 8.
00:29
And if you put this on r, you're going to find that this is equals to this number.
00:37
Now, for the 2b, this was 2a.
00:41
We want to compute the permutations that we can have when we need to select three numbers out of 8.
00:48
So in this question, we are saying that is the same as like 8p3.
00:54
So we need to select.
00:56
We want to check like how many permutations can we have.
01:00
Or possible orders here for these three positions.
01:03
So to compute this, we also have a formula that we can use in factorial, because this here is the same as saying that we need to compute the factorial of 8, which is the total number that we are considering or that we are selecting from, divided by factorial of 8 minus 3, which is 5.
01:32
So if you compute this, you're going to find again, this is the same number as import a, and this is 120...