JEE Main 2024MathematicsFunctionsHardNumerical

JEE Main 2024Functions Question with Solution

JEE Main 2024 (30 Jan Shift 1)

Question

Let A={1,2,3,.7} and let P(A) denote the power set of A. If the number of functions f:AP(A) such that af(a),aA is mn,m and nN and m is least, then m+n is equal to ______.

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Show full solutionCorrect answer: 44
Correct answer
44

Step-by-step explanation

Given,

A={1,2,3,.7}

And f:AP(A) and aA

Also af(a), that means a will be the element of subset as f:AP(A),

Now, total options for 1 will be 26. (Because 26 subsets contains elements1)

Similarly, for every other element we get, total  26×26×26×26×26×26×26=242 subsets.

Now, comparing with mn we get, m=2 & n=42

Hence,  m+n=2+42=44

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About this question

This is a previous-year question from JEE Main 2024, covering the Functions chapter of Mathematics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.