Question

A box contains 10 bulbs 4 of which are defective. If 3 of the bulbs arr drawn randomly without replacement,what is the probability that all 3 bulbs are defective?

Answer 1

bulbs in total = 10 , defective ones = 4 so probability of getting 1 defective bulb =4/10 or 2/5 ,now probability of getting 3 defective bulbs =12/30