00:03
Hello hi here in this question you can see we take a calendar years right we know there are leap years are there so the question is basically from one of the day we are going to select and what will be the probability of those days so first part of the question it is asking us what is the probability that a randomly selected person has a birthday on first day of a month so you know if you take four years 4 years in 4 years out of 4 years 3 years will be 3 l .m .o.
00:50
Non -lapius.
00:51
So it will contain 3 to 365 days.
00:54
And 4th day, 4th year will be a leapio.
00:58
So total there will be 1 ,461 days will be there.
01:05
Right? and every after every 4 years, the same numbers will repeat.
01:11
So knowing that, if you take first part of the question, what is the probability that? that the person selected will be having birthday on first day of a month so first day of a month means how many months are there you know one year there are 12 months are there so 12 into 4 48 month will be there right so probability of getting first day of a month as birthday will be given by i am writing probability of a 48 days will be there out of 1 ,461 this will be the required probability.
01:53
Now take second question.
01:58
What will be the probability? that randomly selected person having birthday on 31st day of month.
02:06
So how many months having 31 days? out of 12 months, seven months in a year has 31 days.
02:19
You can check january, march, may like that, just check.
02:24
You can see seven months other.
02:26
So in a year seven months.
02:27
So in a year, seven month.
02:28
So in a four year, there will be seven into four, that is 28 favorable cases will be there.
02:34
So i'm calling this event as b, in probability of getting 31 days or 30 first day as a birthday will be 28 out of 1 ,461...