If ‘N’ is the number of shafts used, then the total number of feces available for attacking the excavation and construction in tunnels are_________________________?
If ‘N’ is the number of shafts used, then the total number of feces available for attacking the excavation and construction in tunnels are_________________________? A. 2N B. N + 2 C. 2 N + 1D. 2 N + 2