Question

Which of the following is an arithmetic sequence?–20, –25, –30, –35, –45, ...

Answer 1

B) -15.6,-12.9,-10.2,-7.5,-4.8

This is an arithmetic sequence. 

Answer 2

Answer:

The correct option is 2.

Step-by-step explanation:

A sequence is called arithmetic if it has common difference.

In sequence 1,

–20, –25, –30, –35, –45, ...

$d_1=-25-(-20)=-5$

$d_2=-45-(-35)=-10$

$d_1\neq d_2$

Therefore it is not an arithmetic sequence.

In sequence 2, the common difference is

$d=-12.9-(-15.6)=2.7$

Therefore it is an arithmetic sequence and option 2 is correct.

In sequence 3,

$d_1=6.2-3.1=3.1$

$d_2=12.4-6.2=6.2$

$d_1\neq d_2$

Therefore it is not an arithmetic sequence.

In sequence 4,

$d_1=3.6-7.2=-3.6$

$d_2=1.8-3.6=-1.8$

$d_1\neq d_2$

Therefore it is not an arithmetic sequence.

Therefore only option 2 represent arithmetic sequence.