Email
Chat with tutor
logo

Ask Questions, Get Answers

X
 
Questions  >>  CBSE XII  >>  Math  >>  Relations and Functions
Answer
Comment
Share
Q)

If the set A contains 5 elements and the set B contains 6 elements, then the number of one-one and onto mappings from A to B is

\begin{array}{1 1}(A)\quad 720 & (B)\quad 120\\(C)\quad 0 & (D)\quad none\; of\; these\;\end{array}

1 Answer

Comment
A)
Toolbox:
  • 1. A mapping from A to B is one-one
  • if $f(a)=f(b) \qquad a,b \in A$
  • $=> a=b$
  • 2.For every element $y \in B$ there exists an element $ x \in A$ such that $f(x)=y$
  • 3.For a mapping to be both one-one and onto. the number of elements of A and B should be equal or a
  • B subset of A
A has 5 elements
B has 6 elements
Since mumber of elements in B is more than A there cannot be any one-one and onto mapping from A to B
Solution:'c' option is correct
Help Clay6 to be free
Clay6 needs your help to survive. We have roughly 7 lakh students visiting us monthly. We want to keep our services free and improve with prompt help and advanced solutions by adding more teachers and infrastructure.

A small donation from you will help us reach that goal faster. Talk to your parents, teachers and school and spread the word about clay6. You can pay online or send a cheque.

Thanks for your support.
Continue
Please choose your payment mode to continue
Home Ask Homework Questions
Your payment for is successful.
Continue
Clay6 tutors use Telegram* chat app to help students with their questions and doubts.
Do you have the Telegram chat app installed?
Already installed Install now
*Telegram is a chat app like WhatsApp / Facebook Messenger / Skype.
...