We need to find if m > nSTAT 1: \(\frac{m}{n} > 1\)By taking numbers we can easily prove that this option is not sufficient
m = 3, n = 2
=> \(\frac{m}{n}\) = \(\frac{3}{2}\) = 1.5 > 1 and m > n too
m = -3, n = -2
=> \(\frac{m}{n}\) = \(\frac{-3}{-2}\) = 1.5 > 1 BUT m < n
=>
NOT SUFFICIENTSTAT 2: \(\frac{m - n}{n} > \frac{m - n}{m}\)Taking all terms to left hand side we get
\(\frac{m - n}{n} - (\frac{m - n}{m})\) > 0
=> \(\frac{m^2 - n*m - m*n + n^2}{mn})\) > 0
=> \(\frac{m^2 - 2mn + n^2}{mn})\) > 0
=> \(\frac{(m - n)^2}{mn})\) > 0
Now we know that \((m- n)^2\) is non-negative as it is square of a number and will not be equal to 0 also as the expression is > 0
=> \((m- n)^2\) is positive
And we know that if \(\frac{A}{B}\) > 0 and A> 0 then B will also be > 0
=> mn > 0
=> m and n have the same sign
=> EITHER both are positive or both are negative.
But this still doesn't solve the problem as we can take the same cases as the first one to prove it insufficient.
=>
NOT SUFFICIENTTake both the statement together also we have the same problem as we can still use
m = 3, n = 2 and
m = -3 and n = - 2 to prove them insufficient
=>
NOT SUFFICIENTSo,
Answer will be EHope it helps!
Watch the following video to learn How to Solve Inequality Problems