A random variable X follow Poisson distribution such that P(X=1) = 2P(X=2) , then P(X=0) is

The standard deviation of the number of tails in three tosses of a coin is:

If X is a random variable and a, b are real numbers, then which of the following statements are correct?

(A) $E[aX+b] = a E(X) + b$

(B) $Var (aX + b) = a^2 Var (X) + b$

(C) $Var (aX + b) = a Var (X)$

(D) $Var (X) = E(X^2) - [E(X)]^2$

Choose the correct answer from the options given below:

If a person A speaks the truth in 80% cases and the person B speaks the truth in 75% cases, then the probability that they contradict each other in a statement is

A black and a red die are rolled simultaneously. The probability of obtaining a sum greater than 9, given that the black resulted in a 5 is

One person speaks truth in 60% of the cases and another person in 80% of the cases. They are likely to agree in stating the same fact in

The mean of the number of heads in a simultaneous toss of three coins is