SUM OF GEOMETRIC SERIES WORKSHEET

Use the formula for S_n to calculate the sum of following geometric series.

Problem 1 :

5 + 10 + 20 + … to 6 terms

Problem 2 :

4 + 12 + 36 + … to 10 terms

Problem 3 :

1/3 + 1/6 + 1/12 + … to 8 terms

Problem 4 :

100 - 20 + 4 + … to 20 terms

Problem 5 :

16 + 17.6 + 19.36 + … to 50 terms

Problem 6 :

26 – 16.25 + 10. 15625 … to 15 terms

Answer Key

1) S₆ = 315

2) S₁₀= 2(3¹⁰ – 1)

3) S₈= 85/128

4) s₂₀ = 100(1 – (-1/5)²⁰)/(6/5)

5) 16((11)⁵⁰ – 10)

6) s₁₅= 26(1 - (-0.625)¹⁵)/(1.625)