Question

header contains 3 black 4 white and 5 red if two balls are taken out of random find the probability that both of them are black or white

Answer 1

Total number of balls = n(s) = 12

Probability of getting black

P(A) = n(A)/n(s)

P(A) = 3/12

probability of getting white

P(B) = n(B)/n(s)

P(B) = 4/12



Probability of getting both black and white is

P(A U B ) = P(A) + P(B)

P(A U B ) = 3/12 + 4/12

P(A U B ) = 3+4/12

P(A U B ) = 7/12


so answer. is 7/12