For two random variables X and Y, the relation E(XY)=E(X)E(Y) holds good
If P1 (x) and P2 (x) be the marginal probability functions of two independent discrete random variables X and Y, then their joint probability function P(x,y)=
If P(A/B)=1/4 and P( B/A)=1/3, then P(A)/P(B) is equal to
For two events E1 , E2 if P(E1) =1/2 , P(E2)= 1/3 , P( E1 uE2) = 2/3 then P( E1 nE2 ) is equal to
In the simultaneous tossing of two perfect coins, the probability of having atleast one head is
An urn contains 9 balls, two of which are red, three blue and four black. Three balls are drawn at random. The chance that they are of the same colour is