perplexus.info :: Numbers : Rooks on a chessboard

Home > Numbers

Rooks on a chessboard (Posted on 2018-11-26)

How many ways are there to place two rooks on the same column or same row on a nxn chessboard?

See The Solution Submitted by Ady TZIDON

No Rating

Comments: ( Back to comment list | You must be logged in to post comments.)

correcting a typo in puzle's solution

Comment 4 of 4 |

correcting a typo in puzzle's solution:

LAST LINE IN THE OFICIAL SOLUTION SHOULD BE

4*(n^3-n^2) ways since 1+1+2=4

2 white rooks n^3-n^2 ways
2 black rooks n^3-n^2 ways
1 white and 1 black rooks 2* (n^3-n^2 ) ways

answer: 4 * (n^3-n^2 ) ways

Edited on November 30, 2018, 9:39 am

Posted by Ady TZIDON on 2018-11-30 09:37:45

Please log in:

Forums (1)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (6)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:


perplexus dot info