The sample is a geometri sequencethe ratio = -9 / 3 = -3= 27 / -9 = -3so it is clearly a geometric sequencethen the formula of a geometric sequence: an = ar^(n-1)where an is the n terma is the initial termr is the rationn is the number of term an = 3(-3)^(n-1)is the answer
Our sequence is 3,-9,27,........This is a geometric sequence. whose first terms is 3 which is generally denoted by "a" .The common ratio is find out by taking the ration of second term to the first term. In this case it would be ,
Hence r=-3
Now the formula for the nth term of any geometric sequence is given as
=
Hence we now replace the value of a and r in this to find the right answer which is
Hence B option is correct as the first term is not taken into the account in this answer.