Need help ASAP!!!! math problem using Bayes formula and probability tree!?

Here is the problem:

Suppose the probability that an individual has AIDS is .01., the probability of a person testing positive if he or she has AIDS is .95., and the probability of a person testing positive if he or she does not have AIDS is .05.

Find the probability that a person who tests positive has AIDS


-How do you make a probability tree with this problem, and use Bayes Formula?


Thanks

no its for a finite math class in college......and its from a finite math book...the teacher did not make it up

make the first two branches the proportion of people with aids and people without (.01 and .99, respectively). Then make the second row of branches the positive/negative testing (for AIDS, 0.95 and 0.05, w/out aids 0.05 and 0.95). Multiply through; for this excersize, we only care about people who test positive. So the probability of someone testing positive and has AIDS is 0.01*0.95=0.0095 call it A. The Probability of someone testing positive without aids is 0.99*0.05=.0495 call it B. the probability of someone testing positive and having AIDS is A/(A+B)

I hope that this isn't a question for high school or below, because a teacher asking questions about AIDS is offensive and loaded.