Library / /324 of 356

, 2011

Combinatorics Difficulty 3.0 AMC 10/12 Find the answer Canada

Ten circles are all the same size. Each pair of these circles overlap but no circle is exactly on top of another circle. What is the greatest possible total number of intersection points of these ten circles?

(A) $40$ (B) $70$ (C) $80$ (D) $90$ (E) $110$

Want a route through all this instead of an archive? The track puts 2,604 problems in a working order, from Junior Challenge level to the IMO shortlist.

Source: CEMC, University of Waterloo, licensed CC-BY-NC-4.0. Statement reproduced verbatim; metadata (topic, difficulty) added by this project. Solutions are the publisher's, linked not copied.