Evaluate ∑n=1∞3n+5n15n\sum_{n=1}^{\infty} \frac{3^n + 5^n}{15^n}∑n=1∞15n3n+5n.
58\frac{5}{8}85
34\frac{3}{4}43
78\frac{7}{8}87
98\frac{9}{8}89