How old are the youngsters in the class on average? I. The teacher's age is the same as the number of students. II. If the teacher's age is added, the average age is increased by one year.
A. I alone sufficient while II alone not sufficient to answer
B. II alone sufficient while I alone not sufficient to answer
C. Either I or II alone sufficient to answer
D. Both I and II are not sufficient to answer
Answer:D
How old are the youngsters in the class on average? I. The teacher's age is the same as the number of students. II. If the teacher's age is added, the average age is increased by one year.
A. I alone sufficient while II alone not sufficient to answer B. II alone sufficient while I alone not sufficient to answer C. Either I or II alone sufficient to answer D. Both I and II are not sufficient to answer
Explanation: Allow for x children.I stipulate that the teacher's age is x years.II indicates that the average age of (x + 1) people is (x + 1) years.Age of the teacher = (x + 1) (x + 1) - (x2 + 1 + 2x)SQUARE - (1 + 2x) SQUARE=As a result, the age of the teacher cannot be determined.