00:01
In this problem, we are given that there are four coins and all these four coins are tossed and we are required to find the probabilities in the given scenarios.
00:12
So in the first case, we have to get the probability of having exactly three heads.
00:18
So in this case, we will consider tossing of four coins as binomial distribution.
00:23
So the number of trials, that would be four for this distribution.
00:27
And the probability of success, well, that would be the probability to obtain a head when we toss a coin once.
00:34
So that would be, of course, one by two, because we know that a coin has just two possible outcomes.
00:40
So probability to get the head is one by two, and the probability of the failure, well, that would be one minus probability of the success.
00:48
So this would be even one by two.
00:50
And here we will consider x as the random variable, which represents the number of heads.
00:57
That we get in four tarses.
01:00
So here we have to get the probability of obtaining three heads that same as probability that x is equal to three.
01:09
And we will use this formula to get the result of p when x is equal to three.
01:13
So when we plug in the values into this equation, we would get this as 4c3 into one by two, raise to three times one by two raise to one.
01:22
And this upon simplification comes out to be 0 .25...