(a) Events $A$ and $B$ are such that$P(A)=\;\frac{1}{2}, P(B)=\;\frac{7}{12} \;\text{ and }\; P(\overline{A} \cup \overline{B})=\;\frac{1}{4}$Find whether the events $A$ and $B$ are independent or not.OR(b) A bux $B_1$ contains 1 whitc ball and 3 red balls. Another box $B_2$ contains 2 white balls and 3 red balls. If one ball is drawn at random from each of the boxes $B_1$ and $B_2$, then find the probability that the two balls drawn are of the same colour.