urn contains five balls numbered 1 to 5 of which the first three are black and the last two are gold. A sample of size 2 is drawn with replacement. Let B1 denote the event that the fisrt ball drawn is...

urn contains five balls numbered 1 to 5 of which the first three are black and the last two are gold. A sample of size 2 is drawn with replacement. Let B1 denote the event that the fisrt ball drawn is black and B2 denote the event that the second ball is black.