Question
Two cards are drawn simultaneously (or successively without replacement) from a well shuffled pack of 52 cards. Find the mean, variance and standard deviation of the number of kings.
Solution
Let X denote the number of kings obtained in two draws. X takes the values 0, 1, 2.
Let p denote probability of first king.
∴ probability distribution is
Now, Mean of X = E(X) =
Also,
Let p denote probability of first king.
∴ probability distribution is
Now, Mean of X = E(X) =
Also,
