Question

In the Number series given below, one number is missing. Series is followed by five alternatives. One of them is the right answer. Identify and indicate it as per the "Instructions".

$2,35,104,209,....$

• A. $350$
• B. $248$
• C. $256$
• D. $311$
• E. $413$

Answer 1

Answer: (A)

$350$

To solve this question, we use the method of difference.

let $T_5=x$

Now, series is $S:2,35,104,209,x$

Let us take the difference between any 2 adjacent terms be a series $dS$

$dS:33,69,105,(x-209)$

We again take the difference between 2 adjacent terms. Let the series be $ddS:36,36,(x-209-105)$

For the series to be consistent,

$x-209-105=36$

$⟹x=350$

Thus, $\left(A\right)$ must be the answer.