Multiple choice

The average age of 27 girls and the teacher is 14 years. When the teacher's age is excluded, the average age decreases by 1. What is the age (in year) of teacher? 27 लड़कियों और अध्यापक की औसत आयु 14 वर्ष है। यदि अध्यापक की आयु निकाल दी जाए, तो औसत आयु में 1 की कमी हो जाती है। अध्यापक की आयु (वर्षों में) क्या है?

  1. 41

  2. 42

  3. 39

  4. 40
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let the teacher's age be T. Total age of 27 girls + teacher = 28 × 14 = 392 years. When teacher excluded, 27 girls' average = 13 years. Total age of 27 girls = 27 × 13 = 351 years. Teacher's age = 392 - 351 = 41 years. The teacher is older than the average, which makes sense.

Keep practicing — related questions