28 votes 28 votes Let $A$ and $B$ be sets with cardinalities $m$ and $n$ respectively. The number of one-one mappings from $A$ to $B$, when $m < n$, is $m^n$ $^nP_m$ $^mC_n$ $^nC_m$ $^mP_n$ Set Theory & Algebra gate1993 set-theory&algebra functions easy + – Kathleen asked Sep 29, 2014 • recategorized Apr 22, 2021 by Lakshman Bhaiya Kathleen 4.5k views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
Best answer 31 votes 31 votes Answer: B Ref: Page $33$ of http://www.cs.toronto.edu/~stacho/macm101-2.pdf Rajarshi Sarkar answered Apr 26, 2015 • edited Apr 22, 2021 by Lakshman Bhaiya Rajarshi Sarkar comment Share Follow See 1 comment See all 1 1 comment reply Arjun commented Jun 7, 2018 reply Follow Share Ref: 13 votes 13 votes Please log in or register to add a comment.
12 votes 12 votes one to one mapping is permutations of m different thing out of n different thing.. P(n,m) Digvijay Pandey answered Apr 26, 2015 Digvijay Pandey comment Share Follow See all 0 reply Please log in or register to add a comment.
5 votes 5 votes Option B Rishi yadav answered Oct 12, 2017 • edited Nov 30, 2018 by Rishi yadav Rishi yadav comment Share Follow See all 0 reply Please log in or register to add a comment.