Ena was born 4 years after her parents' marriage. Her mother is three years younger than her father and 24 years older than Ena, who is 13 years old. At what age did Ena's father get married?

Let's solve this elegantly using the 'Gap Method' and ignoring the distraction of the current age (13).\n\n1. **Establish the Total Gap:**\n - The Mother is 24 years older than Ena.\n - The Father is 3 years older than the Mother.\n - Therefore, the Father is $(24 + 3) = 27$ years older than Ena. This gap is constant and never changes. [18, 44]\n\n2. **Use Birth as the Reference Point:**\n - At the moment Ena was born, she was 0 years old.\n - Since the Father is always 27 years older than Ena, at her birth, the Father was exactly 27 years old.\n\n3. **Back-Track to Marriage:**\n - We are told Ena was born 4 years *after* the marriage.\n - This means the marriage happened 4 years *before* Ena's birth.\n - Father's Age at Marriage = (Father's Age at Birth) - 4\n - Father's Age at Marriage = $27 - 4 = 23$ years. [7, 35]\n\nNotice we never used the fact that Ena is currently 13. That was just noise.