1. **Problem Statement:** Find Shabnam's age when Aftab's age is 23 years, given Shabnam is 3 years older than Aftab. 2. **Formula:** Shabnam's age $s = a + 3$, where $a$ is Aftab's age. 3. **Substitution:** Replace $a$ with 23: $$s = 23 + 3$$ 4. **Calculation:** $$s = 26$$ 5. **Answer:** Shabnam's age is 26 years when Aftab is 23 years old.