Question

What is the sum of an infinite geometric series if the first term is 81 and the common ratio is 2⁄3?

Answer 1

C

the sum to infinity of a geometric series  = $\frac{a}{1-r}$

where a is the first term and r the common ratio

= $\frac{81}{\frac{1}{3} }$ = 81 × 3 = 243