List of top Quantitative Ability and Data Interpretation Questions on Fraction

If \(x - \frac{1}{x} = y, y-\frac{1}{y} = z, z-\frac{1}{z} = x\), there which of the following equations are true ?
A. \(\frac{1}{x}+\frac{1}{y}+\frac{1}{z}=0\)
B. \(\frac{1}{x^2}+\frac{1}{y^2}+\frac{1}{z^2}=8\)
C. \(\frac{1}{xy}+\frac{1}{yz}+\frac{1}{zx}=-3\)
Choose the correct answer from the options given below:

If \(\frac{1}{x}\) is a positive fraction and \(\frac{1}{y}\) is a negative fraction, then which of the following statements are true? 
(A) \(\frac{1}{x} + \frac{1}{y}\) is positive 
(B) \(\frac{1}{x} - \frac{1}{y}\) is positive 
(C) \(\frac{x - y}{xy}\) is negative 
(D) \(\frac{1}{xy}\) is positive 
(E) \(\frac{1}{x} - \frac{1}{y}\) is positive

If A: B=C: D, then the value of \(\frac{A^2+B^2}{C^2+D^2}\) is