Question

Which of the following statement is incorrect with respect to generalizing the solution using the inclusion-exclusion principle?

(a) including cardinalities of sets

(b) excluding cardinalities of pairwise intersections

(c) excluding cardinalities of triple-wise intersections

(d) excluding cardinalities of quadraple-wise intersections

The question was asked in an internship interview.

This interesting question is from Number Theory in chapter Number Theory of Data Structures & Algorithms II

Answer 1

The correct answer is (c) excluding cardinalities of triple-wise intersections

To explain: According to inclusion-exclusion principle, an intersection is included if the intersecting elements are odd and excluded, if the intersecting elements are even. Hence triple-wise intersections should be included.