Question

Which sequence isn’t a geometric progression?

3,6,9,12
1,5,25,125
2,6,18,54
4,8,16,32

Answer 1

your answer is 3,6,9,12

I hope it will help you

Answer 2

Answer:

3,6,9,12 is not a G.P

Explanation:

Given the following sequence we have to choose that sequence which isn’t a geometric progression.

$\frac{a_2}{a_1}=\frac{a_3}{a_2}=\frac{a_4}{a_3}$

If the above satisfied then the sequence is G.P

Option A: 3,6,9,12

$\frac{6}{3}=\frac{9}{6}=frac{12}{9}$

$2=\frac{3}{2}=\frac{4}{3}$

which is not true.

Hence, above sequence is not a G.P

Option B: 1,5,25,125

$\frac{5}{1}=\frac{25}{5}=\frac{125}{25}$

$5=5=5$

which is true

Hence, G.P

Option C: 2,6,18,54

$\frac{6}{2}=\frac{18}{6}=\frac{54}{18}$

$3=3=3$

which is true

Hence, G.P

Option D: 4,8,16,32

$\frac{8}{4}=\frac{16}{8}=\frac{32}{16}$

$2=2=2$

which is true

Hence, G.P