MathDB

Suppose

A_1,\dots, A_6

are six sets each with four elements and

B_1,\dots,B_n

are

n

sets each with two elements, Let S \equal{} A_1 \cup A_2 \cup \cdots \cup A_6 \equal{} B_1 \cup \cdots \cup B_n. Given that each elements of

S

belogs to exactly four of the

A

's and to exactly three of the

B

's, find

n

8