If A and B are two independent events, the probability that both A and B occur is 1/8 and the probability that neither of them occurs is 3/8. The probability of the occurrence of A 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
In the simultaneous tossing of two perfect coins, the probability of having atleast one head is
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
If P(A/B)=1/4 and P( B/A)=1/3, then P(A)/P(B) is equal to
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)=
For two random variables X and Y, the relation E(XY)=E(X)E(Y) holds good
Var(2X± 3) if Var(X)=1 is
E(X−k)2 is minimum when
The height of persons in a country is a random variable of the type
The mean and variance of a binomial distribution are 8 and 4 respectively. Then P(X=1) is equal to
A probability distribution in which mean is equal to variance is
An experiment succeeds twice as often as it fails. The chance that in the next six trials, there shall be atleast four successes is
The skewness in a binomial distribution will be zero, if
The characteristic function of Poisson distribution is