PrepRung

NDA 2016 Maths · Mathematics · Sets, Relations and Functions · medium

Let A, B and C be sets. 1. A∩(B∪ C)=(A∩ B)∪ C. 2. (A∪ B)'=A'∪ B'.

Single correct option

Let AA, BB and CC be sets. Consider the following statements:
1. A∩(B∪C)=(A∩B)∪CA\cap(B\cup C)=(A\cap B)\cup C.
2. (A∪B)′=A′∪B′(A\cup B)'=A'\cup B'.
Which of the statements given above is/are correct?
  1. A. 1 only
  2. B. 2 only
  3. C. Both 1 and 2
  4. D. Neither 1 nor 2
Show answer and solution

Answer: (D) Neither 1 nor 2

The correct distributive law is A∩(B∪C)=(A∩B)∪(A∩C)A\cap(B\cup C)=(A\cap B)\cup(A\cap C); the statement leaves out AA on the right, so it fails (take CC outside AA). De Morgan's law gives (A∪B)′=A′∩B′(A\cup B)'=A'\cap B', not union. Both are false.
Report a mistake

Original question written in the NDA 2016 Maths pattern and checked twice for the correct answer. Not an official question paper. How we write and check questions · Corrections policy · Report a mistake