Question

In A Coaching Centre the average age of students studying for competitive exams is 22 Years. The average age of boys in the class is 26 years and that of the Girls is 19 years. If the number of boys in the class is 12. Find the number of girls in the class?
1. 12
2. 14
3. 16
4. 18
5. 20

Answer 1

Correct Answer - Option 3 : 16

Calculation:

The average age of the Students is 22

Let the number of the girls be x

The average age of all the students in the class is 22

⇒ [(12 × 26)+(19 × x)]/(12 + x)=22

⇒ 312 + 19X = 22(12 + x)

⇒ 312 + 19X = 22x + 264

⇒ 3x = 48

⇒ x = 16

∴ The number of girls in the class is 16.