$8$ A dozer has been equipped with a three$-$shank ripper. The shank protectors and ripper tips of this dozer must be replaced after $50$ h and $30$ h of dozer ripping operation. Ripping takes place only about $20\%$ of the dozer's total operation time. The local prices of shank protectors and ripper tips including replacement cost are $$130$ and $$60,$ respectively. Calculate the hourly special items cost of this dozer.

Formula for special item cost:

Special cost item $($$$/$h$)=\backslash$Sigma $($Item price including replacement price x Required no$.$ of item$)/($Expected life of item$)$