1981 AHSME Problems/Problem 14
Problem
In a geometric sequence of real numbers, the sum of the first terms is , and the sum of the first terms is . The sum of the first terms is
Solution 1
Denote the sum of the first terms as . Since we know that the sum of the first terms is which is , we have + + = because it is a geometric series. We can quickly see that = , and therefore, the sum of the first terms is
~Arcticturn