You can save lots of time on the exam by not using Bayes if you don’t need it. BTW -It used to be that you couldn’t leave the exams in the last half hour. I was 6/6 in leaving prior to that cut-off. Can’t stand being trapped.
I did it with Bayes and got the answer, but I think for me to try to figure it out with Bayes may even take me longer!!