Restoration of a Vintage Car. The Porsche Shop, founded in $1985$ by Dale Jensen, special$-$izes in the restoration of vintage Porsche automobiles. One of Jensen$$s regular customers asked him to prepare an estimate for the restoration of a $1964$ model $356$SC Porsche. To es$-$timate the time and cost to perform such a restoration, Jensen broke the restoration process into four separate activities: disassembly and initial preparation work $($A$),$ body restoration $($B$),$ engine restoration $($C$),$ and final assembly $($D$).$ Once activity A has been completed, activities B and C can be performed independently of each other; however, activity D can be started only if both activities B and C have been completed. Based on his inspection of the car, Jensen believes that the following time estimates $($in days$)$ are applicable