Question

Enter the common ratio for the geometric sequence below.

5/3
Give your answer in its simplest form.
15,5,
r=

Answer 1

1/3

Explanation:

You want the common ratio (r) of the geometric sequence that begins ...

15, 5, 5/3, ...

Common ratio

The ratio of any term to the one before will give the common ratio. Here, it is probably easiest to find the ratio of the first two (integer) terms:

r = 5/15 = 1/3

The common ratio is 1/3.

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Check

The ratio of the next pair of terms is (5/3)/5 = 1/3, confirming the answer.