Tablel. $1.$ A mining company utilizes a truck$-$shovel system during its stripping operation and a truck$-$backhoe system during the ore extraction phase. Given the conditions outlined in the table above; calculate the following: $($a$)$ The actual haulage hours that is required for a fleet of trucks to satisfy both the weekly stripping and ore extraction demands. $($b$)$ The maximum number of trucks that can be accommodated effectively by two backhoes. $($c$)$ The minimum number of trucks that should be in operation, in order to achieve both the stripping and mining targets. $($d$)$ The minimum number of shovels that is required for the effective execution of the project.