JEE Main 2021 — Functions Question with Solution
From: JEE Main 2021 (Online) 25th February Evening Shift
Question
Let x denote the total number of one-one functions from a set A with 3 elements to a set B with 5 elements and y denote the total number of one-one functions form the set A to the set A B. Then :
Choose an option
Show full solutionCorrect option: C
Correct answer
C2y = 91x
Step-by-step explanation
Number of elements in A = 3
Number of elements in B = 5
Number of elements in A B = 15
Number of one-one function
x = 5 4 3
x = 60
Number of one-one function
y = 15 14 13
y = 15 4 13
y = 60 13
2y = (13)(7x)
2y = 91x
Number of elements in B = 5
Number of elements in A B = 15
Number of one-one function
x = 5 4 3
x = 60
Number of one-one function
y = 15 14 13
y = 15 4 13
y = 60 13
2y = (13)(7x)
2y = 91x
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This is a previous-year question from JEE Main 2021, 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.