Which number will come in place of the question mark (?) in the following series?

Series:

239, 274, 309, 354, 399, 454, ?

Differences check करें:

$274 - 239 = 35$

$309 - 274 = 35$

$354 - 309 = 45$

$399 - 354 = 45$

$454 - 399 = 55$

Pattern:

+35, +35, +45, +45, +55, ...

तो अगला भी +55 होगा।

Next term:

$454 + 55 = 509$

Correct answer: 509