SOLUTION: 2 bulbs are selected from a lot of 12 bulbs which contains 5 defected bulbs. Find the probability of getting 2 defected bulbs. Also find the probability of getting at least 1 defec

Algebra ->  Probability-and-statistics -> SOLUTION: 2 bulbs are selected from a lot of 12 bulbs which contains 5 defected bulbs. Find the probability of getting 2 defected bulbs. Also find the probability of getting at least 1 defec      Log On


   



Question 657829: 2 bulbs are selected from a lot of 12 bulbs which contains 5 defected bulbs. Find the probability of getting 2 defected bulbs. Also find the probability of getting at least 1 defected bulb.
Answer by kevwill(135) About Me  (Show Source):
You can put this solution on YOUR website!
There are ways to choose 2 defective bulbs from the five defective bulbs in the box.
There are ways to choose 2 bulbs from the 12 in the box.
Thus, the probability of picking 2 defective bulbs is 10%2F66+=+5%2F33
There are ways to choose 2 non-defective bulbs from the seven non-defective bulbs in the box.
Thus, the probability of picking 2 non-defective bulbs is 21%2F66+=+7%2F22
Finally, the probability of picking at least one defective bulb is
1+-+7%2F22+=+15%2F22