Q378
The average age of 24 boys and their teacher is 15 years. When the teacher's age is excluded, the average age decreases by 1 year. The age of the teacher is :
A.
38 years
B.
39 years
AnswerC.
40 years
D.
41 years
Answer: Option B
Solution
Answer: Option B
Solution:
The total age of 24 boys and teacher is = 25 × 15
= 375 years
Let the teacher's age = x years
According to the question,
25 × 15 = 24 × 14 + x
375 = 336 + x
x = 39 years