?
The average age of 30 students is 9 years. If the age of their teacher is included, the average age becomes 10 years. The age of the teacher (in years) is :
Answer & Solution
Correct Answer:
Option
D
Let the age of teacher = x years
According to the question,
30 × 9 + x = 31 × 10
270 + x = 310
x = 40 years
According to the question,
30 × 9 + x = 31 × 10
270 + x = 310
x = 40 years
Join the Discussion
Login to post a comment or share your explanation.
Login