Question

Find the um to n terms of the series 10 + 84 + 734 + ………..

      (a) $\frac{9\left ( 9^{n}+1 \right )}{10}+1$                                                    (b)$\frac{9\left ( 9^{n}+1 \right )}{8}+1$

      (c)$\frac{9\left ( 9^{n}-1 \right )}{8}+1$                                                  (d)$\frac{9\left ( 9^{n}-1 \right )}{8}+n^{2}$