What is the sum of the n terms of the series 4 + 12 + 36 + 108 + ...?
hint : sn = a1(1-r^n)/ 1-r where a1 is the first term and r is the common ratio
We need to know how many terms are to be summed......obviously, this sequence would have an unbounded infinite sum because each successive term is three times the previous one....
