3 , 12, 30,. 39 are the first five terms of a sequence . Each term after the first is obtained by adding 9 to the term immediately preceding it .which term in the sequence is equal to 3 + (33 -1) 9?
A
8 th
B
9th
C
32nd
D
33rd
Correct Answer: 33rd
First, term, = 3 General difference = 12 - 3 = 9 Here, 3 + ( 33 - 1) 9 = 3 + 32 × 9 = 291 nth term = a + ( n - 1) d 291 = 3 + ( n - 1) 9 n - 1 = 32 n = 33