A fair die is tossed twice. If the number appearing on the top is less than 3, it is a success. Find the probability distribution of number of successes.
A fair dice is tossed twice.
Every time a throwing dice is an independent event.
Note: P(AՈB) = P(A)P(B) where A and B are independent events.
Let A denote the event of getting a number less than 3 on a single throw of dice.
∴ P(A) = {out of 6 outcomes 1 and 2 are favourable}
P(not A) = P(A’) =
As success is considered when number appearing on dice is less than 3.
Let X denotes the success.
As we are throwing two dice so that we can get success in both throws or either one of them, or we may even not get succeed.
∴ X can take values 0,1 or 2
P(X = 0) = P(not success)× P(not success) = P(A’)× P(A’) =
P(X = 1) = P(A) ×P(A’)+ P(A’)×P(A)
=
P(X = 2) = P(success)× P(success) = P(A)× P(A) =
Now we have pi and xi.
∴ Now we are ready to write the probability distribution for X:-
The following table gives probability distribution: