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Identify which of the sequences below is a geometric sequence.

A 1.3.5, 7.-9....
B 2, 4, -6, 8, 10,
C. 2, 5, 7, 10, 12,
D. 3, 6, 12, 24, 48,

User Darcymason
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1 Answer

2 votes

Answer: Choice D) 3, 6, 12, 24, 48

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Step-by-step explanation:

Sequence A is not geometric. Dividing each term by its previous term does not lead to the same common ratio. For instance, 3/1 = 3 and 5/3 = 1.67

Sequence B is a similar story. We have 4/2 = 2 and -6/4 = -1.5

Sequence C is similar as well. This time 5/2 = 2.5 and 7/5 = 1.4

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Sequence D is geometric because dividing each term over its previous term leads to the same common ratio

6/3 = 2

12/6 = 2

24/12 = 2

48/12 = 2

The common ratio is r = 2.

Put another way, each term is multiplied by 2 to get the next term

3*2 = 6

6*2 = 12

12*2 = 24

24*2 = 48

User Tjorriemorrie
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7.6k points