Question

there are 50 boys in a class whose average is 12years. there are 40 boyd in another class whose average age is 15 years. what is the average age of both the classes taken together.

Answer 1

Total age of 50 boys = 50×12 = 600 years
Total age of 40 boys = 40×12 =480 years
so, Total age of 90 boys = 600+480 = 1080 years
Average age of 90 boys = 1080/90 =12 years

Answer 2

please see the attachment.