Question

in a school of 600 students , average age of boys is 12 years and that of girls is 11 years . if average age of all student is 11 year 9 months . find the number if girls in the school.​

Answer 1

Answer:

average age of school 11 year 9 months

average age of boys is 12 years

average age girls is 11 years

Now

Take difference to find out ratio

( 12 years - 11 years + 9 months):( 11 year- 11 year 9 months)

3 months : 9 months

Therefore

Boy : Girl

9 : 3 = 3 : 1

No girl =1/4 ×600= 150

Answer 2

$\huge\purple{\mid{\fbox{\tt Hi\:Mate}\mid}}$

$\Large\bold{\underline{\red{Question}}}$

In a school of 600 students , average age of boys is 12 years and that of girls is 11 years . if average age of all student is 11 year 9 months. Find the number of girls in the school.

$\Large\fbox\blue{Answer: 150 }$

$\small\bold{\underline{\orange{Given}}}$

Total Number of students in a school = 600 students

Average age of boys = 12 years

Average age of girls = 11 years

Average age of all student = 11 year 9 months

$\small\bold{\underline{\orange{To\: find:}}}$

• Number of girls in the school

$\Large\bold{\underline{\red{Solution}}}$

Find difference to find out ratio

Boys :

(Average age of boys - Average age of all student)

= 12 years - 11 years 9months

= 3 months

Girls :

(Average age of girls - Average age of all student)

= 11 years - 11 years 9months

= 9months

Boys : Girls

= 3 months : 9 months

= 1 month : 3 months

= 1 : 3

Number of girls$= \frac{1}{4} \times 600 = 150$

$\Large\fbox\blue{∴No\: of \: Girls = 150}$

$\Large\color{aqua}Happy\:Learning$

$\Large\fbox\red{Mark\:As\:Brainliest}$