Arithmetic Sequences are of the form

Hence, the difference of 2 consecutive terms gives a constant

Eg. 2,5,8,11

Geometric sequences are of the form

Hence, the quotient of 2 consecutive terms gives a constant

Eg. 2,6,18,54

No.1

The difference of 2 consecutive terms is not constant

The quotient of 2 consecutive terms is not constant

Hence it is neither.

No.2

The difference of 2 consecutive terms gives a constant

Hence it is an arithmetic series.

The difference is

You should try the rest on your own