Chat with tutor

Ask Questions, Get Answers


There are $10$ white and $10$ black balls each set numbered 1,2,3......10. The no. of ways in which they can be arranged so that no two adjacent balls are of same colour is ?

1 Answer

Case (i)
First let us place 10 white balls in (10!) ways.
Then 10 black balls are to be placed in between the white balls in (10!) ways.
Case (ii)
First place 10 black balls in 10! ways and
then place the white balls in between the black balls in 10! ways.
$\therefore $ The required no. of arrangements $= 10!.10!+10!.10!=2\times (10!)^2$
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.
Please choose your payment mode to continue
Home Ask Homework Questions
Your payment for is successful.
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.