In following question, a number series is given with one term missing. Choose the correct alternative that will same pattern and fill in the blank spaces. - Which term of the series 5, 8, 11, 14, … is 320 ?

Answer: C. 106th

Clearly, 5 + 3 = 8,   8 + 3 = 11,   11 + 3 = 14, ....
So, the series is an A.P. in which a = 5 and d = 3.
Let the nnumbers of terms be n.
Then, 320 = 5 + (n - 1) * 3  or (n - 1) = 105 or  n = 106.