Question

What is the eighth term of the geometric sequence 3, 12, 48, 192, ... ?

A. 8,748
B. 16,384
C. 49,152
D. 56,256
E. 196,608

Answer 1

Find the value of r first so you can find by what factor does this sequence increase by.

Answer 2

And how do I do that?

Answer 3

General form of the geometric sequence: a, ar, ar^2, ar^3, ar^4......., ar^n
You can see everyterm increases by multiplication of r.

Answer 4

in order to find r, simply divide one term with the term before.

Answer 5

So 4?

Answer 6

Yep, so the term increases by the multiple of 4, by using that you should be able to find the value of the 8th term.
a is the first term, which is 3 and r is 4
and 8th term can be shown like this
ar^8

Answer 7

ahhh... so it's E, 196,608. Correct?

Answer 8

Yep that would be correct

Answer 9

Thanks!