What is the sum of the first five terms of the geometric sequence in which a1 = 10 and r=1/2

Question

Mathematics

Yamilet Ellis

30 October, 21:22

What is the sum of the first five terms of the geometric sequence in which a1 = 10 and r=1/2

+5

Answers (1)

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Guadalupe Mcclain · Answer 1

Answer:19.375

Step-by-step explanation:

a=10

r=1/2=0.5

Sn=a (1-r^n) / (1-r)

S5=10 (1 - (0.5) ^5) / (1-0.5)

S5=10 (1-0.03125) / (0.5)

S5 = (10 x 0.96875) / (0.5)

S5=9.6875 ➗ 0.5

S5=19.375