It is given that a box containing 30 bulbs of which 5 are defective with each trial independent of other trial
Consider success bulb chosen is defective = 5/30
So the probability of success in the first trial
P1 (success) = 5/30
So the probability of success in the second trial without replacement of the first draw
P2 (success) = 4/29
Probability that both the bulbs chosen are defective, with each trial being independent