Question

The average age of 25 students is 10 years and the average age of another class of 30 students is 15 years. Find the average age of students of the two classes.

A) 12.5 years
B) 12 years
C) 13.5 years
D) 14 years

Answer 1

The combined average age of the students from both classes is found by dividing the total sum of their ages by the combined number of students, resulting in an average age of 13 years.

Step-by-step explanation:

The question asks us to find the average age of students when combining two classes with different average ages. To do this, we need to calculate the total sum of the ages of all the students in both classes and then divide by the combined number of students.

For the first class of 25 students with an average age of 10 years:

• Total age of first class = 25 students × 10 years/student = 250 years

For the second class of 30 students with an average age of 15 years:

• Total age of second class = 30 students × 15 years/student = 450 years

Combined total age = 250 years + 450 years = 700 years

Combined number of students = 25 students + 30 students = 55 students

The combined average age = Combined total age ÷ Combined number of students = 700 years ÷ 55 students = 12.7272 years

Therefore, when rounded to the nearest whole number, the average age of students in both classes is 13 years, which corresponds to option C.