available three excavators a 315DL 320D Japan and 324D Japan

available three excavators a 315DL, 320D (Japan) and 324D (Japan). Their lease/operating costs are S150/hr, $225/hr, and S300/hr. You have to scoop out 5,000 cu. yds. using the maximum rated bucket capacity for each. Assuming that each piece of equipment has adequate front and side reach capacity, which piece of equipment would you use?

Solution

Vol of 1st excavators= 315×150=47250 cu

Vol of 2nd excavators=72000 cu

Vol of 3rd excavators=97200 cu

Total volume=216450 cu

Piece of equipment =216450÷5000=43•29~44