Which of the following is not a geometric sequence?
A. 1, 2, 4, 8
B. 3, 1, -1,-3
C. ½, ¼, 1/8, 1/16
D. 216, 72, 24, 8

Question

Which of the following is not a geometric sequence? 
	A.	1, 2, 4, 8
	B.	3, 1, -1,-3
	C.	½, ¼, 1/8, 1/16
	D.	216, 72, 24, 8

mathstudent55 · Answer

Do you know what to do to find out?

acacia · Answer

@jim_thompson5910 can you help me?

mathstudent55 · Answer

Divide the first number by the second, the second by the third, the third by the fourth. If all divisions are equal, it's geometric.

acacia · Answer

oh okay

mathstudent55 · Answer

Let's use the first one as an example.
Use a calculator for the divisions.
1/2 = 0.5
2/4 = 0.5
4/8 = 0.5
All divisions equal 0.5, and are equal, so the first one is a geometric series.

mathstudent55 · Answer

Now do the same for the others.