Question

What is the sum of a 6-term geometric series if the first term is 8 and the last term is 134,456 ? Answers to choose from.
a)129,513
b)130,624
c)156,864
d)172,846

Answer 1

let the first term = a
then 6th term =ar^5

where r = common ration

can you find r from this information?

Answer 2

i might need some guidance but let me try!

Answer 3

ok

Answer 4

i really dont know how i got this but i ended up with 832 as the common ratio.

Answer 5

6tt term = 134456 = ar^5
ist term = 8

so ar^5/a = r^5 = 134456/8 = 16807