To find the average age of all the teachers in the school, we need to combine the total age of all female and male teachers and then divide by the total number of teachers.
First, let's calculate the total age of the female teachers. Since the average age of the four female teachers is 40, the total age of the female teachers can be calculated as:
Total age of female teachers = Average age * Number of female teachers
Total age of female teachers = 40 * 4 = 160
Next, calculate the total age of the male teachers. With the average age of eight male teachers being 25, the total age of the male teachers is:
Total age of male teachers = Average age * Number of male teachers
Total age of male teachers = 25 * 8 = 200
Now, add the total ages of both male and female teachers to find the combined total age:
Combined total age = 160 + 200 = 360
To find the total number of teachers, simply add the number of female and male teachers:
Total number of teachers = 4 (female) + 8 (male) = 12
Finally, calculate the average age of all the teachers by dividing the combined total age by the total number of teachers:
Average age = Combined total age / Total number of teachers
Average age = 360 / 12 = 30
Therefore, the average age of the teachers in the school is 30.