Fifteen

Fifteen students had an average age of 12 years. When the class teacher came to see them, their average increased by exactly one year. How old was the teacher?

Correct answer:

x =  28

Step-by-step explanation:

 15+115 12+x = 12+1  1615 12+x = 13  12 15+x=13 16  x=28  x=128=28  x=28



Did you find an error or inaccuracy? Feel free to write us. Thank you!







Tips for related online calculators
Looking for help with calculating arithmetic mean?
Looking for a statistical calculator?
Do you have a linear equation or system of equations and are looking for its solution? Or do you have a quadratic equation?

You need to know the following knowledge to solve this word math problem:

Related math problems and questions: