A box contains 12 light bulbs, of which 5 are defective. All bulbs look alike and have equalprobability of being chosen. Two lights are selected with replacement. What is theprobability that at least one is defective?Please help

Question
Answer:
Answer: 95/144


Explanation:

There are 12 light bulbs.
There are 5 defective bulbs.
There are 7 not defective bulbs.

P (at least one defective) = first one defective or second one defective or both defective.

P (at least one defective) = (5/12)(7/12) + (7/12)(5/12) + (5/12)(5/12) = 95/144
solved
general 10 months ago 6683