Problem 13 from prior weeks.
Correct!
Explanation:
Solution: 29 comes next. This is the series of integers who digits' sums are prime numbers. So 11's digits summed are 1 + 1 = 2, a prime number; 12's are 1+2 = 3; so the next number after 25 whose digits sum to a prime number is 29 (2 + 9 = 11).