Verified Solution • 2025–26 Session moderate

QJEEM21Ma26c2: JEE Main 2021 Mathematics - Class 11 JEEM21Ma26c2 Solution: Let x denote the total number of one-one functions from a set A …

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 ×\times B. Then :

Multiple Choice Options

  • A 2y = 273x
  • B y = 91x
  • C 2y = 91x
  • D y = 273x

Step-by-Step Verified Solution

Number of elements in A = 3

Number of elements in B = 5

Number of elements in A ×\times B = 15

JEE Main 2021 (Online) 25th February Evening Shift Mathematics - Functions Question 96 English Explanation 1

Number of one-one function

x = 5 ×\times 4 ×\times 3

x = 60

JEE Main 2021 (Online) 25th February Evening Shift Mathematics - Functions Question 96 English Explanation 2

Number of one-one function

y = 15 ×\times 14 ×\times 13

y = 15 ×\times 4 ×\times 144{{14} \over 4} ×\times 13

y = 60 ×\times 72{7 \over 2} ×\times 13

2y = (13)(7x)

2y = 91x

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