Find the missing number in the set: (2, 3, 11), (3, 4, 19), (4, 5, ?)

Explanation

The third number is (a + 1)(b + 1) − 1: 3 × 4 − 1 = 11, 4 × 5 − 1 = 19, so 5 × 6 − 1 = 29.