Question

2 years ago the mean age of 40 people was 11 years.Now a person left the ground and the mean age is changed to 12 years.find the age of the person who left the group

Answer 1

Answer: hope i help you

28

Step-by-step explanation:

x/40 = 11         ,       x/39  =  12

x = 40 * 11        ,       x = 39 * 12

x= 440             ,       x =  468  

Δx = 468 - 440

      = 28