Given: A box containing 30 bulbs of which 5 are defective.Each trail is independent of the other trial.
To find: the probability that both the bulbs are chosen are defective.
Let , success :bulb chosen is defective .i.e\(\frac{5}{30}\)
Now , the Probability of success in the first trial is
P1(success) = \(\frac{5}{30}\)
Probability of success in the second trial without replacement of the first draw is given by
P2(success) = \(\frac{4}{29}\)
Hence , the probability that both the bulbs are chosen are defective,with each trial being independent is given by