Question

What is the sum of the first five terms of a geometric series with a1 = 20 and r = 1/4?

Answer 1

For the answer to the question above,
The first term is 20 
The second term is 20* 1/4 = 5 
The third term is 5 * 1/4 = 5/4 
The 4th term is 5/4 * 1/4 = 5/16 
The 5th term is 5/16 * 1/4 = 5/64 

Sum is therefore 20 + 5 + 5/4 + 5/16 + 5/64 
To complete my answer,
= (1280 + 320 + 80 + 20 + 5) / 64 
= 1705/64

I hope my answer helped you. Have a nice day!

Answer 2

Hello there.
What is the sum of the first five terms of a geometric series with a1 = 20 and r = 1/4?

Express your answer as an improper fraction in lowest terms without using spaces.

= 1705/64