Question

4. Which of the following is a geometric sequence?

Answer 1

Answer: Choice D

Explanation:

We can verify this by noticing the ratio between adjacent terms is the same

• term2/term1 = -16/4 = -4
• term3/term2 = 64/(-16) = -4
• term4/term3 = -256/64 = -4

The common ratio is -4. Each time we need a new term, multiply the previous term by -4. Example: -16*(-4) = 64.