00:01
In this problem, we have been asked in how many ways can two letters be chosen from the set a, b, c, d, e, f, if order is important and no repeats are allowed.
00:11
So, no repeats are allowed, so we can use the concepts of combination and permutation.
00:17
And in this case, order is important, so we will have to use the concept of permutation.
00:23
Now, we have the set of letters as a, b, c, d, e, f, so that's a total of six letters.
00:28
And out of those six letters, we need to select any two letters, and this can be done in six p -two ways.
00:35
And we're using p here, which represents permutation, and we use permutation since order is important...