The average age of eleven students is 20 years. If the age of the teacher is also included, the average age increased by 10%. The age of teacher is : 11 छात्रों की औसत आयु 20 वर्ष है। यदि अध्यापक की आयु की भी शामिल कर लिया जाये, तो औसत आयु 10% बढ़ जाती है। अध्यापक की आयु ज्ञात कीजिए।

Initial average age of 11 students = 20 years, so total age = 11 × 20 = 220 years. When teacher is added (total 12 people), new average = 20 × 1.10 = 22 years. New total age = 12 × 22 = 264 years. Teacher's age = 264 - 220 = 44 years. The teacher's age raises the average by 10% because the teacher is significantly older than the student average.