plz explain 2

{1 point} This problem involves the career plans of students in a biology class. Assume that the class consists of 35 percent freshmen, 20 percent sophomores, 25 percentjUhiors, and 20 percent seniors. Assume further that 40 peroeht of the freshmen, 3O peroeht of the sophomores, 25 percent of thejuniors, and 20 percent of the seniors plan to go to medical school. One student is selected at random from the class. {1) What is the probability that the student plans to go to medical school? ::: {2) If the student plans to go to medical school, what is the probability that she is ajunior? EEE {1 point} Rework problem 16 from section 3.4 of your text, involving university students' math backgrounds. Assume that 55 percent of the students at the university have taken 4 years of high school math. Of those with four years of high school math, 3t) percent plan to major in science. Of those without 4 years, only 20 percent plan to major in science. You stop a student at random. If the student plans ID major in SEiEHCB, what is the probability that \"\"5 student had TDIJI' years Of high school math? (1 point} Rework problem 19 from section 3.4 of your text, involving the rental cars with navigation systems. Assume that the car lot contains 30 percent BMWs. 35 percent Corvettes, and 35 percent Volvcs. Of the BMWs, 20 percent have navigation systems, 10 percent of the Corvettes have navigation systems, and 80 percent of the Volvos have navigation systems. You are assigned a car at random. If the car has a navigation system, what is the probability that it is not a BMW