How do you determine whether the sequence #5, 15, 45, 135,...# is geometric and if it is, what is the common ratio?

1 Answer
May 9, 2017

Answer:

Common ratio is #3#

Explanation:

Sequence : # 5, 15, 45, 135,.......#

#a_1=5 , a_2=15, a_3=45 , a_4=135, .......#

#a_2/a_1= 15/5 =3 , a_3/a_2= 45/15 =3 , a_4/a_3= 135/45 =3 , .....#

In this sequence the ratio of each term and the previous term is

constant , so it is geometric sequnce and constant is #3#.

Common ratio is #3# [Ans]