Question

What is the common difference in the following arithmetic sequence?

A. –11
B. –1
C. 1
D. 11

Answer 1

The answer is D

-12+11=-1

-1+11=10

10+11=21

You add because it is an arithmatic sequence rather than a geometric sequence

Answer 2

The Common difference is 11.

D is the correct option.

Explanation:

In an arithmetic sequence, the difference of consecutive terms are equal and we call this common difference.

Therefore, in order to find the common difference, we find the difference of any two consecutive terms.

Let us find the difference of second and first term.

From the given table, we have

`a_1=-12,a_2=-1`

Hence, common difference is given by

`d=a_2-a_1\\d=-1-(-12)\\d=-1+12\\d=11`

Hence, the common difference is 11.

D is the correct option.