00:01
Item a we need to compute what is the probability that at least we are going to observe two hats here.
00:09
So here two plus means that at least two hats.
00:13
So first we need to determine what kind of outcome we can have when we toss a coin three times.
00:24
So basic what we can have is head, head, head.
00:28
So head for all of them.
00:29
Then we can have head, head, and then a tail.
00:35
We can have head, tail, head.
00:40
We can have head, head, tail, tail, tail.
00:47
We can have here, tail, head, head.
00:53
We can have tail, head, tail, tail, and tail, tail, tail.
00:59
Head.
01:01
So basically for each one of the tosses we have two options.
01:05
So that's why that in the end we have eight outcomes.
01:11
So now that we know each outcome we can compute this as the number of outcomes that has two heads at least two.
01:19
So one, two, three, four, and that's it out of the eight outcomes.
01:26
So this is 0 .5.
01:29
Now for item b we want the probability.
01:32
Of a or c and this was b here.
01:38
A or c means that at least one head or the number of heads is odd.
01:46
So the number of heads is odd...