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JEE Main 2022 · MathsNumerical answerNumerical valueHardMulti-step

JEE Main 25 July 2022, Shift 2, Maths Q21

Question 21 of 90 in this shift, Maths question 21 of 30, Section B.

Let

A=\{1,2,3,4,5,6,7\}

. Define

B=\{T\subseteq A:\text{either }1\notin T\text{ or }2\in T\}

and

C=\{T\subseteq A:T\text{ the sum of all the elements of }T\text{ is a prime number}\}

. Then the number of elements in the set

B\cup C

is ___________.

Official answer

107

NTA final key.

Chapter: Relations and Functions
Topic: Sets and Relations
Idea tested: Subsets and Proper Subsets

Same idea in other shifts

Asked 2× in all

26 Jul 2022, Shift 2 · Q21Let $A=\{1,2,3,4,5,6,7\}$ and $B=\{3,6,7,9\}$ . Then the number of elements in the set $\{C\subseteq A: C\cap B\neq\phi\}$ is ________EasyNumerical value

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.