Posted by viru on .
The Probability of drawing two black balls in succession from a bag containing 4 red and 3 black balls when the ball first drawn is
a) replaced
b) not replaced

math/probability 
Reiny,
a) if replaced, prob = (3/7)(3/7) = 9/49
b) if not replaced prob = (3/7)(2/6) = 1/7