Question

Identify the following series as geometric or arithmetic. Also identify the series as infinite or finite. -5, -10, -15, -20,

Answer 1

arithmetic

finite

Explanation:

Correct on Odyssey

Answer 2

It is an Arithmetic series which is finite.

Explanation:

Given series,

-5, -10, -15, -20

∵ A series is called Geometric series if there is a constant ratio ( called common ratio ) in the consecutive terms,

While, it is called Arithmetic series if there is a constant difference in consecutive terms,

`\because (-10)/(-5)\\eq (-15)/(-10)\\eq (-20)/(-15)`

That is, it is not a GP,

Now, -10 + (-5) = -15 - (-10) = -20 - (-15)

Thus, it is an AP,

Since, a series having finite number of elements is called finite series otherwise it is called infinite series,

Here, the number of elements is 4 ( finite )

Therefore, the given series is finite.