The average age of 10 students and their teacher is 15 years. The average age of the first seven students is 15 yr and that of the last three is 11 yr. What is the teacher's age?
Answers
Answered by
11
Answer:
Step-by-step explanation:
The sum of the ages of students and teachers =11*15=165
The sum of first seven students age=7*15=105
The sum of last three students age=3*11=33
The sum of age of 10 students =105+33
=138
Teacher age =165-138
=27years
Answered by
0
Given:
- Number of students and their teacher = 11
- The average age of the first seven students = 15 year for each
- The average age of the last three students = 11 year for each
To Find:
- The teacher's age.
Solution:
- The average age of all the 10 students and their teacher collectively = 11*15 = 165 years.
- The average age of the first seven students collectively = 7*15 = 105 years.
- The average age of the last three students collectively = 11*3 = 33 years.
- The total age of just the students = age of first seven students+age of last three students = 105+33 = 138 years.
- We got to know the age of all ten students and the age of all 10 students and their teacher also.
- To find the age of only the teacher we need to subtract the age of 10 students + 1 teacher from the age of all the 10 students.
- The age of teacher = 165-138 = 27 years.
The age of the teacher = 27 years.
Similar questions