Question

the average of the students of a class is 12 years.the average age of 15 of them is 10 years and the average age of the remaining is 13 years. how many students are there in the class

Answer 1

Answer:

The total number of students in the class is 45.

Step-by-step explanation:

Let the total number of students in the class be x.

Therefore, the total sum of ages of students = 12 x

Average age of 15 students = 10

Therefore, the total sum of ages of 15 students = 150

number of remaining students = x - 13

Total sum of ages of remaining students = 12 x - 150

So, we have the following equation,

(12 x - 150)/ (x - 15) = 13

12 x - 150 = 13 x - 195

x = 45