00:01
Are these permutations or combinations? so first, what's the difference? in both cases, you're picking things from a collection without replacement.
00:10
So there's no repetition.
00:12
Then you ask yourself, does the order in which you select them matter? if yes, you have permutations.
00:26
If no, you have combinations.
00:31
So let's look at the first example here.
00:34
We're picking three committees from eight students.
00:39
So we have eight students, we need to pick three of them to go into a committee.
00:43
Does it matter what order i pick them? well, no, it doesn't.
00:47
They're just going into committees.
00:49
So this is combinations.
00:53
Determining the top three winners in a mathwizb.
00:57
So does the order matter here? yes.
01:01
This is permutations.
01:02
I could pick the same three winners, but they could be in a different order.
01:07
Maybe one person gets first, then second, then third.
01:10
That would be different to the first person getting second place, and then first and then third...