A group of 20 students attempting a mathematical challenge have an average age of 11.When their teacher is included their average age is 12. What is the age of the teacher

Answers

Answer:

Teacher’s age is 32.

Step-by-step explanation:

How you count the average age for people is: (age of person 1 + age of person 2 … ) / number of people = average age

Let’s start by observing that we’ve got 2 equations coming from the text:

average of just students 20 students x 11 (average for a student) = sum of age of students 20 x 11 = 220

average of student and teacher let’s say x is age of teacher together students & teacher is 20 + 1 = 21 people (20 students x 11 + x)/ (20 + 1) = 12 (220 + x) / 21 = 12 220 + x = 12 * 21 x = 12 *21 – 220 x = 252 – 220 x = 32

Answer:Step-by-step explanation:

How you count the average age for people is:

(age of person 1 + age of person 2 … ) / number of people = average age

average of just students20 students x 11 (average for a student) = sum of age of students

20 x 11 = 220

average of student and teacherlet’s say x is age of teacher

together students & teacher is 20 + 1 = 21 people

(20 students x 11 + x)/ (20 + 1) = 12

(220 + x) / 21 = 12

220 + x = 12 * 21

x = 12 *21 – 220

x = 252 – 220

x = 32