Student: There are different 15 circles. What is the number of the greatest possible points with which the circles intersect?
Options:
(A) 390
(B) 100
(C) 110
(D) 180
(E) 210.
Another student: Let's say, hmmm...
Maximum points of intersection between n different circles = n*(n - 1) = 15*14 = 210 Final answer: (E).