Question

What is the average age of children in the class ?
A. Age of the teacher is as many yrs as the number of children.
B. Average age increased by 2 yrs, if the teacher's age is also included.

• A. If the data in statement A alone is sufficient to answer the question
• B. If the data in statement B alone is sufficient to answer the question.
• C. If the data either in statement A alone or in statement B alone is sufficient to answer the question
• D. If the data given in both statements A and B together are not sufficient to answer the question
• E. If the data in both statements A and B together are necessary to answer the question.

Answer 1

The correct option is D If the data given in both statements A and B together are not sufficient to answer the question

Let the number of children be x ...(i)
From statement A we get, teacher's age = x
From statement B we get, average age of $(x+1)$ persons $=x+2$
$\therefore$ Teacher's age $=(x+2)(x+1)=x^2$
$=x^2+3x+2-x^2=3x+2$ ...(ii)
From (i) and (ii) also we cannot find the average age of the children.