Question

The average age of 12 girls in a class is 22 years and of 18 boys in a class is 24 years.Average age of class is

Answer 1

Step 1

The average age of 12 girls  =  22 years

           (sum of the age of 12 girls)  / 12  =  22

sum of the age of 12 girls   =  12 x 22

   sum of the age of 12 girls  = 264

Step 2

The average age of 18 boys = 24

sum of the age of 18 boys  = 24 x 18  =  432

Step 3

Sum of the age of 12 girls  = 264

sum of the age of 18 boys  = 432

sum of the age of 30 student (12+18)  = 696

Step 4

Average age of class = sum of the age of 30 students / 30

                                    = 696 / 30

                                   = 23.2