UPSC CDS Math Average Questions

Let the number of male employees be x and female employees be y.
Now, total age of male employees
= average age × number of employees
=52x
Total age of female employees =42y
Now, mean age of all employees
=‌

52x+42y

x+y

According to the question,
‌

52x+42y

x+y

=50
⇒‌‌52x+42y=50x+50y
⇒‌‌2x=8y
⇒‌‌‌

x

y

=‌

4

1

i.e. ‌‌x:y=4:1
So, 80% of population is male and 20% of population is female.