The computing system of WITS is currently undergoing shutdown repairs. Previous shutdowns have been due to either hardware failure, software failure or electronic failure. The system is forced to shut down 43% of the time when it experiences hardware problems, 9% of the time when it experiences software problems, and 95% of the time when it experiences electronic problems. Maintenance engineers have determined that the probability of the computing system having hardware failure is 0.45, software and electronic failure 0.25 and 0.30 respectively. Given that there is a shutdown, the probability that it is due to hardware failure is