00:01
All right, in your question, you're figuring out probabilities to deal with when birthdays can occur, and we are to exclude leap years in this discussion.
00:09
So what we're working with is a typical year that would have 365 days on the calendar.
00:17
Okay, so what is the probability that your birthday is not november 8th? well, there are 364 days that are not november 8th.
00:28
So it's 364 out of 365.
00:32
Let me just check real quick.
00:34
See, it does not tell us that we are to have our answers in any decimal form or anything like that.
00:42
So i think we should leave them in simplified fraction form.
00:46
And this would be your simplified fraction form.
00:49
If you know you need decimals, just take the numerator divided by the denominator.
00:55
Part b, probability that your birthday is not on the first of a month.
00:59
Well, there are 12 months.
01:02
So that means each of those months would have a first, and we're going to take 12 days away from 365, and that's going to give me 353.
01:12
There's 353 days that are not on the first of the month out of 365.
01:23
And i will have to check.
01:26
I don't think that one's simplifiable either, so we're just going to keep moving.
01:31
Okay, the next one, birthday is not.
01:33
On the 31st? well, the trick to this one is figure out what months actually have a 31st day to figure out how many 31st there are.
01:43
January has a 31st, march has a 31st, may, july, august, october, and december...