<span>W = event where white marble is drawn B = event where black marble is drawn
The two events W and B are independent. This is because the marble taken out on the first draw is put back into the bag. Since W and B are independent, we can use this rule
P(W and B) = P(w)*P(B)
Use the rule to get
P(W and B) = P(W)*P(B) P(W and B) = (1/2)*(1/4) P(W and B) = (1*1)/(2*4)
P(W and B) = 1/8
1/8 is equivalent to 0.125. Use long division or a calculator
