There-are-n-white-and-n-red-balls-marked-1-2-3-n-The-number-of-ways-we-can-arrange-these-balls-in-a-row-so-that-neighbouring-balls-are-of-different-colours-is-

Question Number 21799 by Tinkutara last updated on 04/Oct/17

There are n white and n red balls

marked 1, 2, 3, \dots . n . The number of

ways we can arrange these balls in a

row so that neighbouring balls are of

different colours is

Commented by mrW1 last updated on 06/Oct/17

2 {(n!)}^{2} ?

Commented by Tinkutara last updated on 06/Oct/17

Yes .