. Number of one one functions from A to B where
A to B where n(A) = 4, n(B) = 5 .
A: 4
B: 5
C: 120
D: 90
Best Answer
Explanation:
Given: n(A)=4
n(B)=5
For one-one mapping of the functions, we can select 4 elements out of 5 from set B in 5C4 ways.
And then we can map those selected elements with 4 elements of set B in 4! ways.
So the number of mappings from set A to set
B =5C4 4!
=5!4!(5-4)!4!
=120
Final Answer:
The number of one - one functions from A to B are 120. Hence option C is the correct choice.
Related questions
