A five station indexing assembly machine has a cycle time of $3$s$.$ The quality level of the parts supplied to the workhead is $1\mathrm{.}1,2\mathrm{.}3,0\mathrm{.}6,1\mathrm{.}5$ and $0\mathrm{.}2\%$ respectively. The average time taken to correct a fault and restart the machine is $30$s$.$ Assuming that every defective part will cause a machine fault estimate: a$)$ The percentage downtime for the machine $(36\mathrm{.}3\%)$