CAT 1991 Question 25

Question 25

If $$y = f(x)$$ and $$f(x) = \frac{(1-x)}{(1 + x)}$$, which of the following is true?


Among all options only D satisfies the given equations as follows:
$$f(y) = \frac{1-y}{1+y}$$
and for x:
$$y + xy = 1-x$$
$$x(1+y) = 1-y$$
$$x= \frac{1-y}{1+y}$$
Hence $$x=f(y)$$

View Video Solution

Create a FREE account and get:

  • All Quant CAT Formulas and shortcuts PDF
  • 20+ CAT previous papers with solutions PDF
  • Top 500 CAT Solved Questions for Free


Register with


Boost your Prep!

Download App