stonecold wrote:

If m and n are positive integers such that m > n, what is the remainder when m^2 – n^2 is divided by 21?

Statement 1: The remainder when (m + n) is divided by 21 is 1.

Statement 2: The remainder when (m – n) is divided by 21 is 1.

FROM STATEMENT - I ( INSUFFICIENT)We do not have any relationship between the value of m & n as such it won't be possible for us to find the remainder of \(\frac{(m^2 – n^2)}{21}\), since m & n can take any values...

FROM STATEMENT - I ( INSUFFICIENT)We do not have any relationship between the value of m & n as such it won't be possible for us to find the remainder of \(\frac{(m^2 – n^2)}{21}\), since m & n can take any values...

COMBINE STATEMENT I & II (SUFFICIENT)\(\frac{(m^2 – n^2)}{21} = \frac{( m+n )( m-n )}{21}\) = \(Remainder \ 1\)

Hence BOTH statements (1) and (2) TOGETHER are sufficient to answer the question asked, but NEITHER statement ALONE is sufficient to answer the question asked, answer will be (C)Similar Question to practice

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Thanks and Regards

Abhishek....

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