Answer
The sequence is neither geometric nor arithmetic.
Work Step by Step
The given sequence is
$120,60,20,5,...$
Calculate ratio between each pair of consecutive terms.
$\frac{120}{60}=2$
$\frac{60}{20}=3$
$\frac{20}{5}=4$
There is no common ratio.
So, the sequence is not geometric.
Calculate difference between each pair of consecutive terms.
$60-120=-60$
$20-60=-40$
$5-20=-15$
There is no common difference.
So, the sequence is not arithmetic.
The sequence is neither geometric nor arithmetic.
