Which of the following numbers will replace the question mark (?) in the given series?4, 7, 17, 38, 72, 123, 193, 286, 408, ?
- A521
- B561
- C512
- D516
Solution & Step-by-step Explanation
Let's find the difference between consecutive terms in the series: Now let's compute the second-level differences (differences of differences): Notice that the second-level differences are consecutive prime numbers: .The next prime number after is .Therefore:Next first-level difference = Missing number =