If A and B are events such that ​P(A)=0.6 and ​P(A∪​B)=0.8​, find​ P(B) when ​(a) A and B are mutually​ exclusive;
​(b) A and B are independent.

The random variable x is the number of occurrences of an event over an interval of ten minutes. it can be assumed that the probability of an occurrence is the same in any two-time periods of an equal length. it is known that the mean number of occurrences in ten minutes is 5.3. the appropriate probability distribution for the random variable