00:01
In number 32, we're talking about the probability of having different birthdays at different times of the year, essentially.
00:07
So the first question, part a, asks, what's the probability that somebody has a birthday on the first of a month? this one's a little bit more straightforward because every month has a first.
00:20
And so that would mean that there are 12 firsts throughout the year.
00:24
And we're told to just think of a regular year, not a leap year.
00:27
So that would be out of 365 days.
00:30
So 12 possibilities of it being a first out of 365 possibilities, which is about 0 .033 or 3 .3%.
00:47
Part b asks the probability of being the 31st.
00:52
Now this isn't going to be the same because not every month has a 31st.
00:57
There are only seven months that do.
00:59
So 7 .30 firsts out of 365 dates.
01:05
And that would be 0 .019 or 1 .9%.
01:16
Part c asks the probability that somebody has a birthday in december.
01:21
And i would look at this kind of the same way as we were doing the others and look in terms of days.
01:27
There are 31 days in december out of 365...