In Prof. Leahy's class, if a student does homework most days, the chance of passing the course is 90%. On the other hand, if a student does not do homework most days, the chance of passing the course is only 30%. Prof. Leahy claims that 70% of his students do homework on a regular basis. If a student is chosen at random from Prof. Leahy's class, find the following probabilities: a. p(the student did not do homework and he/she passed the course)
b. p(the student did not do homework given that she/he passed the course)