Question

Under what condition any set A will be a subset of B?

(a) if all elements of set B are also present in set A

(b) if all elements of set A are also present in set B

(c) if A contains more elements than B

(d) if B contains more elements than A

This question was posed to me in an international level competition.

The doubt is from Checksum, Complexity Classes & NP Complete Problems in division Checksum, Complexity Classes & NP Complete Problems of Data Structures & Algorithms II

Answer 1

Right option is (b) if all elements of set A are also present in set B

Easy explanation - Any set A will be called a subset of set B if all elements of set A are also present in set B. So in such a case set A will be a part of set B.