6 are defective, which means 74 are not defective.
If I select 2 at random, what are the odds at least one is defective.
There are 80 light bulbs: 6 are Defective, 74 are Good.
If I select 2 at random, what is the probability at least one is Defective.
The opposite of "at least one defective? is "NO defective".
What is the probability of no Defective (both are Good)?
There are:[color=beige] .[/color] possible pairs of bulbs.
There are:[color=beige] .[/color] pairs of Good bulbs.
It could be solved like this . . .