Find the variance of first n natural numbers.(iB If PA)PUB).PAn B). th

1.	Find the variance of first n natural numbers.(iB If PA)PUB).PAn B). then find the value ofP(A n B) and P(AU B).
Answer» We knowP( A u B ) = P(A)+P(B)-P(A n B)P( A n B' ) = P( A n B ) - P( B ) Given, P(A) = 2/3, P(B) =1/2, P(A n B) = 1/6 Then,P( A u B ) = 2/3 + 1/2 - 1/6 = (4 + 3 - 1)/6 = 6/6 = 1P( A n B') = 1/6 - 1/2 = (1 - 3)/6 = - 2/6 = - 1/3

Find the variance of first n natural numbers.(iB If PA)PUB).PAn B). then find the value ofP(A n B) and P(AU B).

Answer»

We knowP( A u B ) = P(A)+P(B)-P(A n B)P( A n B' ) = P( A n B ) - P( B )

Given, P(A) = 2/3, P(B) =1/2, P(A n B) = 1/6

Then,P( A u B ) = 2/3 + 1/2 - 1/6 = (4 + 3 - 1)/6 = 6/6 = 1P( A n B') = 1/6 - 1/2 = (1 - 3)/6 = - 2/6 = - 1/3