00:01
Okay, so first we have math.
00:05
Now we have four letters here.
00:07
So how do we arrange them? that's just going to be, we have four times three times two times one ways.
00:11
That's just going to be four factorial, which is equal to 24.
00:16
Four times three times two times one, so 24 ways.
00:19
For b, we have the word book, b -o -o -k.
00:24
So again, we have four letters.
00:27
So generally, it would be four factorial, but we have two o's here.
00:31
So the unique arrangements would be four factorial divided by two factorial.
00:38
So that's going to be four times three times two divided by two.
00:41
So that's going to be 24 divided by two, which is going to be 12.
00:46
We have 12 ways here.
00:49
C, we have the word calculus.
00:52
So c -a -l -c -u -s.
00:57
So we have eight letters...