What are the numbers that come next in these sequences: 3,9,27,81?

1 Answer
Feb 15, 2016

Answer:

The 5th term:#= 243#

Explanation:

#3, 9 , 27, 81#

The above sequence is identified as a geometric sequence because a common ratio is maintained throughout the sequence.

The common ratio #(r)# is obtained by dividing a term by its preceding term:

1) #r = 9/3 =color(blue)(3#

We need to find the fifth term of the sequence:

The 5th term can be obtained through formula:

# T_n = ar^(n-1) #

(note: #a# denotes the first term of the series)
#a=3#

#T_5= 3xx 3^((5-1))#

#= 3xx 3^(4)#

#= 3xx 81#

#= 243#