MATH SOLVE

2 months ago

Q:
# 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

Accepted Solution

A:

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

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