Probability

Question

Assume the bag contains 19 basketballs, 6 of which have defective valves. You choose 3 out of the bag randomly.

What is the probability that at least 1 will have a defective valve?

Answer 1

Use the formula P(1)=19C3xp^3q^16

where p is the probability  of a favorable event in our case 6/19 where                                                                    q is the probability of an unfavorable event in our case 13/19

19C3=19!/(3!x(19-3)!)=969

P(1)=969x(6/19)^3x(13/19)^16=0.07