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. 2 N + 2

B. 2 N + 1

C. N + 2

D. 2N

Found an error? Read our corrections policy and submit a sourced correction below. You can also share a useful explanation in your own words.

Discuss the answer or suggest a sourced correction
Thank you for contributing.
Your comment was submitted and will appear after editorial review.

Your email is used only for moderation and is never displayed. Spam, copied material and fabricated endorsements are rejected.