Question

The average age of 12 boys is 17 years and of 15 girls is 16 years. What is the average age of all boys and girls?

A) 16.54 yrs
B) 16.56 yrs
C) 16.44 yrs
D) 16.21 yrs

Answer 1

Step-by-step explanation:

Total sum of boys age = No. of Boys * Average age;

Total sum of boys age = 12*17;

= 204;

Total sum of girls age = 15*16;

= 240;

Average of all boys and girls = (204+240)/(12+15);

= 444/27 = 16.44 Option C is right

Answer 2

Average = 16.44 years

Step-by-step explanation:

$\text{Average} =\frac{\text{Sum of all observation}}{\text{Number of observation}}$

Average of 12 boys = 17 years

Average × Number of observation = Sum of all observation

⇒ 17 × 12 = Sum of all observation

⇒ 204 = Sum of all observation of 12 boys

Average of 15 boys = 16 years

Average × Number of observation = Sum of all observation

⇒ 16 × 15 = Sum of all observation

⇒ 240 = Sum of all observation of 15 girls

Sum of all boys and girls = 204 + 240 = 444

Number of boys and girls = 12 + 15 = 27

$\text{Average} =\frac{\text{Sum of all observation}}{\text{Number of observation}}$

$\text{Average} =\frac{444}{27}$

Average = 16.44 years

To learn more...

1. The average age of all the student of a class is 18 years. the average age of boys of the class is 20 years and that of the girls is 15 years. if the number of girls in the class is 20, then find the number of boys in the class.

https://brainly.in/question/5213017

2. The average age of adult class is 40 years. 12 new student with an average age of 32 years join the class thereby decreasing the average of the class by 4 year the original strength of class was

https://brainly.in/question/4602727