Consider a box containing 80 pairs of snow mittens.

Among these 160 mittens 8 are defective, i.e. (have some kind of defects e.g., broken seams ripped inner layer, etc.) Assume any mitten can be defective at random.

(a) What is the probability of finding a defect-free pair of mittens in the box?

(b) Let N be the random variable counting the number of defect-free pairs of mittens in the box. Find E[N] and Var[N].

(Hint: Use indicator random variables.)