00:01
So this question asks us to arrange the six letters, a, b, c, d, e, and f without repeating any of the letters.
00:08
So we can imagine we have six slots, basically, that we have to fill.
00:12
So in the first slot, we have six options to choose from.
00:15
And then since we can't repeat any, in the second option, we only have five letters to choose from.
00:20
And then in the third option, we only have four letters to choose from.
00:24
And then three, then two, then one.
00:26
So this is six factorial or 720 ways.
00:30
To arrange these six letters without repeating any of them.
00:34
Now, the second part of this question asks us, of these 720 ways, how many begin and end with the consonant? so once again, let's imagine we have six slots...