An arithmetic sequence is a sequence in which the numbers have a common distance between them, for example: 2,3,4,5,... the common distance is 1.
A geometric sequence is a sequence in which a common ratio is used. This problem has a common ratio of 1/2.
1.6/2=0/8
0.8/2=0.4
0.4/2=0.2
Hope this helped! (:
