Question: 93, 309, 434, 498, 521, 533
[A].309
434
498
521
[A].
[B].
[C].
[D].
Answer: Option D
Explanation:
The correct pattern is + 63, + 53, + 43, + 33, …..
So, 521 is wrong and must be replaced by (498 + 33) i.e. 525.