Problem $7$

Consider two learning management systems $($let$\text{'}$s denote them by A and B $-$ such as Canvas or TRACS$).$ Both systems go down for maintenance for $2$ hours every month. System A goes down once per month for $2$ hours, whereas system B goes down $6$ times per month for $20$ minutes each time. Answer the following questions $[2$ pts each$]$:

$($a$)$ What is the availability of System A$?$

$($b$)$ What is the availability of System B$?$

$($c$)$ What is the MTBF of System A$?$

$($d$)$ What is the MTBF of System B$?$