Question

2. 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
D
there in the class ?
.
please explain in more simple way
​

Answer 1

Answer:

2. 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

D

there in the class ?

.

please explain in more simple way

Answer 2

Answer:

45

Step-by-step explanation:

Let the total no. of students in class be x .

Then.

Sum of ages of all students = Mean age× Total no. of students

=12×x=12x

Similary, sum of ages of 15 students = 15×10=150

And, Sum of ages of remaining students = (x−15)×13

So, 12x=150+(x−15)×13

12x=150+13x−195

x=45

Thus, The correct answer is 45