Question

The greatest possible number of points of intersection of 9 different straight lines
and 9 different circles in a plane is
(A) 117
(B) 153
(C) 270
(D) none of these

(WITH STEP BY STEP ECPLAINATION PLEASE) ​

Answer 1

Step-by-step explanation:

There are nine circle. Any two pairs of circles can intersect at most at 2 points. So the maximum number of points of intersection is when all the possible combinations of pairs of circles intersect at two points. So the resulting points of intersection of these pairs are 2∗36=72.