[Apurva Rastogi]

2 white squares are chosen such that they are not in same square and same column.how many such squares are formed ?:confused:

[glassdoc]

I'm not sure but I think 16.

[ebaines]

Your question is not very clear - I suggest you retype it precisely as the problem was given to you. For now I will assume that what you meant to ask is this:

Two white squares are chosen such that they are not in the same row or same column. How many ways can such squares be chosen?

To solve this, first consider how many ways the first square can be chosen - there are 32 white squares on a chess board, so you have 32 choices for the first white square. Once you have picked that first square, how many remaining white squares can you choose from that are not in the same row or column? If you look at a chess board you will see that there are 3 other white squars in the same row, and 3 in the same column, for a total of 6 squares that are unavailable. You're also not allowed to pick the original square either, so that's 7 that are not allowed. Which means there are 32-7 = 25 squares to choose from for the second square. So now, can you work out how many total combinations there are for selecting the two white squares?

[survivorboi]

Wait... so don't really understand this myself, so it's like Ebaines like, 25*24*23*22*21*20*19 and so on??

[albear]

If I'm understanding the question properly then 49 I think , I'm a bit tired so my math might be off :D

[ebaines]

You have 32 white squares to choose from for the first choice, and for any one of those you have 25 remaining white squares that are not in the same row or column. Hence total number of ways to select two white squares that are not in the same row or coumns is 32*25 = 800.

However, since the OP never clarified what the question is, this is just conjecture.

Albear or glassdoc - what is your understanding of the problem? How did you get 16?

[albear]

I went by how many differentsquares of 2x2 can you make with two diagonally touching white squares

[ebaines]

i went by how many differentsquares of 2x2 can you make with two diagonally touching white squares

Thanks, but that would give 7 x 7 = 49 squares. And nothing in the original post specifies 2 x 2 squares. It's impossible to agree on an answer if we can't agree on the question!

[albear]

yea I canged my answer after some hasty recalculationg :), yea I know it doesn't say 2x2 squares, but that's what I took it to mean by 'forming squares of 2 whites connecting but not in the same question'