SSC GD Constable 5 Feb 2025 Shift 2 Paper

Total age $=$ Average age × Total number of individuals
Teacher's age $=$ Total age $($ with teacher $)-$ Total age (without teacher)
Calculation:
Total age of 30 students $=18\times 30$
Total age of 30 students = 540
Total age of group (with teacher) $=19\times 31$
Total age of group (with teacher) $=589$
Teacher's age $=$ Total age $($ with teacher $)-$ Total age (without teacher)
⇒ Teacher's age $=589-540$
⇒ Teacher's age $=49$