00:01
There is the given worth here, which is the mathematics.
00:05
So this is mathematics.
00:12
So in order to get the rearrangement here, we're going to use the repeating permutation here.
00:21
This is use the repeated permutation because there are some numbers are repeating.
00:29
If we just change their places, nothing has changed because of that.
00:32
We have to use the repeating permutation.
00:34
Or the repeated permutation.
00:36
So first of all, let's find how many letters do we have? so we have, this is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11.
00:50
So there are 11 numbers here.
00:53
So the number of rearrangement, which is equal to, this is 11 factorial divided by.
01:02
So for the repeated permutation, which is n factorial divided by, this is r1 factor, r2 factorial, this is the formula we are going to use.
01:10
And how many repeating numbers do we have here? so how many m do we have? we have 1, 2m.
01:16
So that means i'm going to divide this by 2 factorial times.
01:21
And by the way, how many a do we have? we have 1, 2a...