Van Helsing is set to appear in the nal exam of a Field Theory course, in which she is a student. If she has breakfast before the exam she is three times as likely to write all the answers on her own than c0py from anyone else. If she does not eat breakfast, she is three times as likely to c0py than to work independently. If she works independently her score is (approximately) a Gaussian (70, 10) random variable. If she decides to copy, then she tosses a fair coin and copies all her answers from her friend Igor if heads appear, and from her classmate Drac, if tails appear. If she copies her answers from Igor then her score is (approximately) a Gaussian (73, 10) random variable. However if she Chooses Drac, then he tells her all the wrong answers on purpose, in which case her score is zero. A student fails if s / he scores 39.49 marks or below, although all the remaining grades are awared relative to the class average. The chances of Van Helsing having breakfast on the day of the exam are two out of ve. If she fails the exam then what is the probability that she did not have breakfast