00:01
Here the experiment is rolling in die.
00:06
So first we can write the sample space.
00:09
The sample space will be 1, 2, 3, 4, 5 and 6.
00:17
Now, the first part of the question is, you have to find the probability of rolling a this or a number, greater than 3.
00:35
From this statement itself, we can see that the two events are not mutually exclusive, so we can find that probability of rolling a 6.
00:45
From this, we can see that there is only one output.
00:49
So the total probability of rolling a 6 is 1 by 6.
00:53
And we can write even that greater than 3, probability of getting greater than 3.
01:00
A number greater than three.
01:02
So greater than three there are four three favorable cases that is four, five, six and the total favorable cases are six and we can see the intersection of these two also.
01:14
That is rolling a six intersection a number greater than three.
01:19
So you can see that rolling greater than three and six there is only one optimum which is common to both.
01:27
So here the favorable case probability is 1 by 6.
01:30
Now we can find the probability that rolling a 6 or u.
01:36
Or means union, that is a number greater than 3.
01:40
Using a decent theorem, we can write probability of rolling a 6 plus probability of rolling a number greater than 3 minus the intersection of this, that is 1 by 6.
01:52
And on calculation, this is equal to 3 by 6, which is 1 by 2.
01:57
So here the required probability is 1 by 2...