If the mean and variance of a binomial distribution are 4 and 2 respectively, then probability of getting 2 heads is

For two events $$\mathrm{A}$$ and $$\mathrm{B}, \mathrm{P}(\mathrm{A} \cup \mathrm{B})=\frac{5}{6}, \mathrm{P}(\mathrm{A})=\frac{1}{6}, \mathrm{P}(\mathrm{B})=\frac{2}{3}$$, then $$\mathrm{A}$$ and $$\mathrm{B}$$ are

A random variable X has following distribution

Then P (2 $$\le$$ x < 5) =

A coin is tossed three times. If X denotes the absolute difference between the number of heads and the number of tails, then P (X = 1) =