The sum of an inifnite geometric series is 10. The first term and ratio are equal. What is the first term?
The formula for the sum of an infinite geometric series is: Sum = a / (1 - r)
where a is the first term, r is the common ratio and |r| < 1.
If the sum is 10 and the first term and ratio are equal (call this value x):
10 = x / (1 - x)
10(1 - x) = x (cross multiply)
10 - 10x = x
10 = 11x
x = 10/11