Question
Download Solution PDFThere are 15 students in a class. The average age of the students and the teacher of the class is 15 years. The average age of the teacher and the students is 2 years more than that of students. What is the age of the class teacher?
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFConcept Used:-
The average of the group of numbers is the ratio of the sum of all the numbers given to the total number.
The formula to found the average is given below.
⇒ Average = (sum of all the observation) / (Total number of observation)
Explanation:-
Suppose the age of the class teacher is x years.
Also, let sum of ages of students is y years.
Total students in the class = 15.
The average age of students and teacher = 15 years.
⇒ (x + y) / 16 = 15
⇒ (x + y) = 240 ....(1)
The average age of the teacher and the students is 2 years more than that of students. Thus,
⇒ (y / 15) + 2 = 15
⇒ y =13 × 15
⇒ y = 195
Put this value in equation (1),
⇒ (x + y) = 240
⇒ (x + 195) = 240
⇒ x = 45 years
So, the age of the class teacher is 45 years.
Hence, the correct option is 4.
Last updated on Jul 7, 2025
-> The UGC NET Answer Key 2025 June was released on the official website ugcnet.nta.ac.in on 06th July 2025.
-> The UGC NET June 2025 exam will be conducted from 25th to 29th June 2025.
-> The UGC-NET exam takes place for 85 subjects, to determine the eligibility for 'Junior Research Fellowship’ and ‘Assistant Professor’ posts, as well as for PhD. admissions.
-> The exam is conducted bi-annually - in June and December cycles.
-> The exam comprises two papers - Paper I and Paper II. Paper I consists of 50 questions and Paper II consists of 100 questions.
-> The candidates who are preparing for the exam can check the UGC NET Previous Year Papers and UGC NET Test Series to boost their preparations.