Question 59
Find the maximum number of sets which simultaneously satisfy the following 3 conditions:
(i) any of the sets consists of 4 elements;
(ii) any two different sets have exactly 2 common elements;
(iii) no two elements are common to all the sets.
(i) any of the sets consists of 4 elements;
(ii) any two different sets have exactly 2 common elements;
(iii) no two elements are common to all the sets.