In a driving school 60% of students pass licensing test....

Guys to begin with click on this link: http://hem.bredband.net/nimkam1/LastScan.jpg
and zoom if you have firefox, otherwise just rightclick on it, and use an external photoeditor so you can see it. My technical expertise unfortunately doesnt come much further.



QUESTION!
In an american carschool 60% of the attendants pass the official test for the driverslicense. Before doing the offical test have to do a prior test at the carschool.(test nr1)
I has shown that among those attendents who passed the official test (test nr2) on the first try 80% of them had passed the carschooltest (nr1).
Among those attendants who don't pass the official test (nr2) on the first try only 10%has passed test nr 1,.

a) Calculate the probability that an attandant both passes the carschools and the official test?
b) Calculate the probability that an attendandt passes the carschooltest?
c) Calculate the probability that an attendandt who have passed the carschooltest passes the official test for drivers licence.
d) Calculate the probability that an attendant who has managed to pass at least one test now have passed the official test.


So far MY work is stuck after I find this through the formulas on the pic I posted above. We need to clarify Events here. I set
Event A: The attendandt passes the official test for the drivers license for the first time.
Event B: The attendendants passes both the tests,
Event C: The attendendants who passes the carschooltest
Event D: The attendtands who doesnt pass the official test.

But here I get stuck! How am I to chose between statistically indepent and so on (check the pic I linked to in the beginning of the post)

So you're too busy with more important things to do your own homework, but you'll be glad to help us do it for you...? I certainly hope I'm misunderstanding that....

The image at the link was unreadable to me, and requiring people to surf, decipher, save, tweak, print, and decipher some more is hardly helpful. If you're wanting people to help you with a question, it is only polite to make that question clear. You expect us to write out the mathematics clearly and accessibly; surely you can show us the same courtesy...?

Please reply with a clear statement of the exercises and their instructions, showing all of your work and reasoning so far. Thank you.

Eliz.

As I PM:ed you have tried for very long time and no, if you want to help me here I´ll stay for however long you want

I wont go have fun, I will stay put alone tonight, I just cant solve it, and have no friends at new university, so kind if sucks, my mother read 60p mathematics like 30years ago but forgot most. Stokastik variable, big F, sigma, etc. This is basic, and I missed the masic seminars so any help would be appreciated. If you think Im a slacker I can scan the next weeks tasks which I have already done about probablity function, cumulative distributionfunctions, excpeted value, and standard deviation NO!
But the simple part the Probablity involving aUB BUA I missed those seminars.
Ah well if noone wants to help.

Thank you anyway

Still trying, I´ll try all night if it takes me,

I`m still trying to solve them trough the regular formulas that is in the pic I attached to my post. But no success, gonna stay awake all night if it takes me, shouldnt have missed those seminers, all the other seminers are easy but its strange how the first chapter of Newbold can be tricky.

Please type out your work. Your latest scanned image is so large that, even on my cable-Internet connection, I'm still waiting (a couple minutes, so far) for the picture to finish loading, and all that's visible at this point are some standard probability rules (which aren't needed). Presumably the work you've done is down at the bottom of the scan, but I doubt many (any?) will wait around for that portion finally to become visible.

Thank you.

Eliz.

....

The work I have done can be found in my thread at the bottom, but since you seem to be after finding faults then thanks anyway. I´ll hope someone else will help