We are told \(s - \frac{s}{1} < \frac{t}{1} - t \).
We can rearrange that to be: \(\frac{s^2-1}{s}<\frac{1-t^2}{t}\)
(1) Because \(s>1\), we know then that \(t\) must be a positive fraction where \(0<t<1\) in order for \(\frac{s^2-1}{s}<\frac{1-t^2}{t}\) to hold. Therefore \(s>t\)
If \(t\) is negative, \(\frac{1-t^2}{t}\) will be negative because of the denominator.
If \(t\) is greater than \(1\), \(\frac{1-t^2}{t}\) will be negative because of the numerator.
This leaves \(0<t<1\).
SUFFICIENT(2)The problem here is that we know \(t>1\), however, we do not know enough about \(s\). As we do not know whether \(s\) is positive or negative we cannot cross multiply. However, we can plug in values to see if we can deduce that \(s>t\) or \(t<s\).
Values plugged into \(\frac{s^2-1}{s}<\frac{1-t^2}{t}\):
Let s = -2 and t = 2
\(\frac{-3}{2}<\frac{1}{2}\). The statement we are plugging into holds and here and s<t.
Let s = 1 and t = 0.5
\(0 < \frac{3}{2}\)
The statement we are plugging into holds, however, in this case s>t.
INSUFFICIENTAnswer A