Question

Which one of the following is not an Arithmetic progression ?

• A. 1, 3, 5, 7 .....
• B. 2, 4, 8, 16 ....
• C. -5, -10, -15, -20 .....
• D. 12, 16, 20, 24 .....

Answer 1

The Correct Option is B

An arithmetic progression (AP) is a sequence of numbers in which the difference of any two successive members is a constant. This difference is known as the common difference (d). Let's analyze each option:

1. 1, 3, 5, 7, ...

The difference between successive terms is 2 (3-1=2, 5-3=2, 7-5=2). This is an AP.

2. 2, 4, 8, 16, ...

The difference between terms varies (4-2=2, 8-4=4, 16-8=8). This is not constant, so it is not an AP.

3. -5, -10, -15, -20, ...

The difference between successive terms is -5 (-10+5=-5, -15+5=-10, -20+5=-15). This is an AP.

4. 12, 16, 20, 24, ...

The difference is 4 (16-12=4, 20-16=4, 24-20=4). This is an AP.

Hence, the sequence which is not an arithmetic progression is 2, 4, 8, 16, ...