Question. There are different 5 circles. What is the number of the greatest possible points with which the circles intersect?
Options:
(A) 20
(B) 10
(C) 15
(D) 22
(E) 21
Answer. (A)
What step-by-step reasoning justifies that answer?
Reasoning: Maximum points of intersection between n different circles = n*(n - 1) = 5*4 = 20