from the lot of 30 bulbs which include 6 defectives , a sample of 4 bulbs is drawn with replacement . find the prob. distribution of the no. of defective bulbs.
Asked by prabhakar p | 14th Mar, 2013, 06:48: AM
Whenever, the question is talking about the replacements, you should not use combinations, untill and unless you are treating each event(or draw) as an independent.
In this case, probability of drawing a defective bulb = (30-6)/30 = 24/30 = 4/5
Probability of drawing a defective bulb = 1/5.
Now, let X be the number of defective bulbs drawn
Answered by | 14th Mar, 2013, 07:25: AM
Kindly Sign up for a personalised experience
- Ask Study Doubts
- Sample Papers
- Past Year Papers
- Textbook Solutions
Verify mobile number
Enter the OTP sent to your number