An infinite geometric series has a common ratio 1/5 and sum 16. What is the first term of the series?

Guest Aug 24, 2021

#1**0 **

Let S be the sum and a is the first term:

S = S/5 + a = 16

5S = S + 5a = 80

4S = 5a

4 x 16 = 5a

64 = 5a

a = $\boxed{\frac{64}5}$

SparklingWater2 Aug 24, 2021