perplexus.info :: Numbers : Sum Square Grid Row & Column ≠ 0

Sum Square Grid Row & Column ≠ 0 (Posted on 2010-04-29)

Each cell of a 1997x1997 square grid contains either +1 or -1, with no cell being vacant.

The product of all the numbers in the ith row, and the product of all the numbers in the ith column are respectively denoted by R_i and C_i.

1997
Prove that Σ_i=1(R_i + C_i) is always nonzero.

See The Solution Submitted by K Sengupta

Rating: 3.0000 (3 votes)

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re: Solution - (MS Word Formatting!?)

| Comment 2 of 6 |

(In reply to Solution by farcear)

I copied the previous post from MS Word to prevent random Firefox crash from losing whatever I had typed but it seems to have added random tags too.

Do you use Normal or Pre-Formatted?

Posted by farcear on 2010-04-29 12:23:46

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