<p>A recent Government Accounting Office report found that the detection of weapons or bombs has not improved much since 2003. In a separate Federal Aviation Administration test of the effectiveness of airport screening systems, 40 percent of explosives, 30 percent of guns, and 70 percent of knives planted by government agents made it through such security checkpoints. </p>
<p>Assume that on average 1 suitcase in 10,000 has a bomb in it. Find the probability that no alarm is sounded for a suitcase that has no bomb. </p>
<p>Ok, for a suitcase that has no bomb, that's 9999/10000. But then i don't how to go from there?
The answer is 0.69993.</p>
<p>There’s not enough information to solve the problem (at least, not that you posted). You have no information about how the detectors work on suitcases without bombs, so what can you do?</p>
<p>but aren’t bombs considered explosives?</p>
<p>Yes. But the problem only tells you how many of the suitcases that do have explosives are detected. That gives no information on how many of the suitcases that don’t are detected.</p>
<p>Maybe this statement will also help: It is said that the occurrence of false-positives in airport screenings has been about 30%.false-positves are disruptive. having one’s luggage flagged as possibly carrying a bomb stigmatizes innocent passengers as potential terrorist suspects.</p>
<p>Oh wait wow! nevermind i understand!</p>
<p>^that’s not how i did it. Where did you get the .4 and the .3 from?</p>
<p>Lol Jerry you deleted your post!</p>
<p>i know. lol. But apparently you got it. So there’s no point in posting that post.</p>
<p>^I understand but the way you did seems awkward. What i simply did was multiply 0.7, which i got from subtracting .3 (false-positive) from 1, by 9999/10000. I have no clue where you got .4 and .3 from and then added?</p>
<p>well, i was sort of guessing. My teacher was rushing through probability, but I will understand that topic entirely next week as I’m studying for AP exams. But that way is much more logical. I was trying to understand if my way works logically.</p>