Multiple choice

In these questions, a question is given followed by information in three statements consider the information in all the three statements and decide the information in which statement(s) is not necessarily required, to answer the question and therefore can be dispensed with. Indicate your answer accordingly. What is the age of class teacher? I. There are 11 students in the class. II. The average age of students and class teacher is 14 years. III. The average age of students and teacher is 3 years more than the average age of the students.

  1. I and III

  2. I and II

  3. II and either I or III

  4. All

  5. None of these
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Let T be teacher's age, n=11 students. From II: (T+sum of students)/12=14 → T+sum=168. From III: ((T+sum)/12)-((sum)/11)=3. Substituting from II: 14-(sum/11)=3 → sum/11=11 → sum=121. Then T=168-121=47. All three statements are necessary - none can be dispensed with. Hence 'None of these' is correct.

Keep practicing — related questions