Question

is 100,20,4 arithmetic?

Answer 1

Answer:

No. The sequence is not arithmetic, but rather geometric.

Step-by-step explanation:

Arithmetic Sequence

Arithmetic Sequence is a sequence that has common difference.

To find a common difference:-

$\displaystyle \large{a_{n + 1} - a_n = d}$

Thus:-

20-100 = -80

4-20 = -16

Since both are not common, the sequence is not arithmetic.

Geometric Sequence

Geometric Sequence is a sequence that has common ratio.

To find a common ratio:-

$\displaystyle \large{ \frac{a_{n + 1}}{a_n} = r}$

Thus:-

20/100 = 1/5

4/20 = 1/5

Since both are common, the sequence is geometric.

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