In a shipment of 100 televisions, 6 are defective. If a person buys two televisions from that shipment, what is the probability that both are defective?
First off, i want to thank you for your answers, i really, obsolutely helped me understand what and how to start.
Secondly, i use the method that you just explained to me in the previous problem. But when i worked this problem, the answer is incorrect.
This is how i did it: There are 100 TV, 6 of them are defective. The probability of getting the first fective one is 6/100 and the probability of the second defective one is also 6/100. Therefore, the chance of getting both defective TV is (6/100)*(6/100)= 9/2500.
But that answer is incorrect, the right answer is 1/330. Why is that?
2007-01-26 11:13:16 · 7 answers · asked by Ha!! 2 in Science & Mathematics ➔ Mathematics
The last problem was tricky because you were dealing with percents, not exact numbers like this TV situation.
In this case:
First tv you pick is 6/100. The second tv you pick is 5/99 - because you have 99 tvs left after the first pick, and there are only 5 defective ones left.
so, it's 6/100 * 5/99 which reduces to 1/330
2007-01-26 11:21:59 · answer #1 · answered by Mathematica 7 · 1⤊ 0⤋
You first take the probability that the first computer will be defective: 6/100.
Now you have 99 computers left and are assuming that you already have one of the defective computers.
Therefore, the probability that the second computer will be defective is 5/99. There are 5 defective computers and 99 overall.
The answer is 6/100 times 5/99...1/330
2007-01-26 11:19:55 · answer #2 · answered by Joy M 7 · 1⤊ 0⤋
I'm not sure what the previous question was, but I think your problem here is that you are not accounting for the defective TV you removed from the set.
Instead of (6/100)*(6/100), it should be (6/100)*(5/99), since your set has changed. This gives 30/9900 = 1/330
2007-01-26 11:20:14 · answer #3 · answered by Michael C 2 · 1⤊ 0⤋
the probability of the first being defective is 6/100
the probability of the second, however, is 5/99.
so 6/100*5/99=30/9900
which more than likely reduces to the correct answer
2007-01-26 11:20:31 · answer #4 · answered by Some Guy 2 · 1⤊ 0⤋
(6/100) = (3/50)
ANS : (6/100)((6 - 1)/(100 - 1)) = (3/50)(5/99) = (15/4950) = 1/330
ANS : 1 out of 330 or (1/330)
Don't forget that he bought 2 of them, so that would be 6 out of 100 at first, take one of them away, leaves a possibility of 5 defective tvs out of 99 televisions, so the probability is (6/100)(5/99) or (1/330)
2007-01-26 15:24:02 · answer #5 · answered by Sherman81 6 · 0⤊ 0⤋
6/100 is the first one being defective
5/99 is the second one being defective
2007-01-26 11:22:15 · answer #6 · answered by Professor Maddie 4 · 0⤊ 0⤋
It depends on which truck they fell off of.
2007-01-26 11:18:27 · answer #7 · answered by killmylandlord 4 · 0⤊ 2⤋