Which one of the following is a closed form expression for the generating…

GATE · 2018 · CS · Computer Science & IT

1. A.

   $\frac{3}{(1-x)^2}$

2. B.

   $\frac{3x}{(1-x)^2}$

3. C.

   $\frac{2-x}{(1-x)^2}$

4. D.

   $\frac{3-x}{(1-x)^2}$

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