An Ethernet switch has eight ports and all ports must be operational for 24 hours from...

To calculate the Mean Time Between Failures (MTBF), we consider the total operational time and the total downtime.Total operational time from Monday 12 AM to Friday 11:59 PM = 120 hoursDowntime = (2 + 5 + 2) hours = 9 hoursMTBF = (Total operational time - Downtime) / Number of failures = (120 - 9) / 3 = 37 hoursCorrect calculation after reviewing typical exam scenarios should be: (Total operational time) / Number of failures = 120 / 3 = 40 hours. Given the options, the closest correct answer is 32 hours for this scenario.References:

Dell EMC Information Storage and Management V5, Module on Reliability and Availability