# Math Help - Converging or Diverging...??

1. ## Converging or Diverging...??

Determine whether the series: $\sum_{n=1}^\infty$ 25^-n+2 . 16^n+1converges or diverges. If it converges then find its sum

Can I have some hints in solving this question..

2. Originally Posted by Angel Rox
Determine whether the series: $\sum_{n=1}^\infty$ 25^-n+2 . 16^n+1converges or diverges. If it converges then find its sum

Can I have some hints in solving this question..
Two hints:

1. $25^{-(n+2)} \cdot 16^{n+1} = \frac{16^{n+1}}{25^{n+2}} = \frac{16}{25^2} \cdot \left( \frac{16}{25} \right)^n$.

2. Sum of an infinite geometric series.