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Saturday, 31 October

JEE Main 2021 · MathsMultiple choiceSingle correctMediumConceptual

JEE Main 25 July 2021, Shift 2, Maths Q79

Question 79 of 90 in this shift, Maths question 19 of 30, Section A.

Consider functions f:A→Bf:A\to B and g:B→Cg:B\to C (A,B,C⊆RA,B,C\subseteq\mathbf{R}) such that (g∘f)−1(g\circ f)^{-1} exists, then :
  1. (1)ff is one-one and gg is ontoOfficial answer
  2. (2)ff and gg both are one-one
  3. (3)ff is onto and gg is one-one
  4. (4)ff and gg both are onto

Official answer

Option 1

NTA final key.

Chapter
Relations and Functions
Topic
No close match in our taxonomy
Idea tested
No close match in our taxonomy

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.