What should come in place of the question mark (?) in the given series?
517, 494, 461, ?, 365, 302

Given: 517, 494, 461, ?, 365, 302

Logic: the differences decrease by 10 each time: -23, -33, -43, -53, -63.

517 - 23 = 494
494 - 33 = 461
461 - 43 = 418
418 - 53 = 365
365 - 63 = 302

So, the missing term is 418.

Thus, correct option is (b).