$($c$)$ Nine processes, when run independently, are all found to block for $67\mathrm{.}5\%$ of their execution times. The processes are run together under a concurrent operating system operating system. Calculate the CPU utilisation in this situation.

$3$

$($d$)$ In a certain computer system, the average blocking time for all processes is $80\%.$ Table $1$ summarises the arrival time of four processes and their required CPU time to complete.

Table $1$

$\backslash$table$[[$Process$,$Arrival time,$\backslash$table$[[$Required CPU time to complete$],[$in minutes$]]],[1,,],[2,10$:$00,4],[3,10$:$10,3],[4,10$:$15,2],[10$:$20,2,]]$

Determine how long it will take to complete all the processes.

$9$