The average age of a class of 40 students is 15 years. If the teacher’s age is added, the average increases by 0.5 years. What is the teacher’s age?
34
53
35
43
Description:
Answer: C) 35 years
Explanation:
Total age of 40 students = 40 × 15 = 600
New total = 41 × 15.5 = 635.5
Teacher’s age = 635.5 − 600 = 35.5
Since 35.5 isn’t listed, choosing closest.
Correct Answer: C) 35 years