Question

Determine whether the sequence is arithmetic. If so, find the common difference.

128, 64, 32, 16,8...
a. Arithmetic sequence, d = 24
b. Arithmetic sequence, d=-120
c. Arithmetic sequence, d = 8
d. Arithmetic sequence, d = -8
e. Not an arithmetic sequence

Answer 1

E. Not an arithmetic sequence

Explanation:

The difference between 128 and 64 is 64, but the different between 64 and 32 is 32.

Therefore this is an geometric sequence with a common ratio of 1/2.