Question

Suppose you just received a shipment of twelve televisions. Two of the televisions are defective. If two televisions are randomly​ selected, compute the probability that both televisions work. What is the probability at least one of the two televisions does not​ work?

Answer 1

P(both work) = ((10-3)/10)*((10-3-1)/9) = (7/10)*(6/9) = 42/90

P(at least one does not work) = 1 - P(both work) = 1 - 42/90 = 48/90 = 24/45.