Answer:
3
5
Explanation:
Remember that odds for plus odds against must be 1. Therefore, 20 out of 50 of the DVRs are defective, so 30 out of 50 would work.
30
50
simplifies into
3
5
, so that would be the probability of you picking out a DVR that works, and the probability of picking one that does not work would be the leftover
2
5
. Or, if you're answering with a percent, you would have a 60% chance of picking a working DVR.
I hope this helps, I know the explanation isn't really clear, but I can't really think of another way to explain it.Step-by-step explanation:
