To find the probability using the Bayes' theorem.
A test on zoology is to be given next week. Suppose 75 percent of the students study for the test and 25 percent do not. If a student studies for the exam, the probability that he or she will pass is 0.90. If the student does not study, the probability that he or she will pass is 20 percent. Given that the student passed the test, what is the probability that he or she studied?
[HINT: create a tree diagram and use Bayes' theorm formula regarding conditional probability.
Find P(s), P(ns), P(p|s),P(p|ns).]