Question

The average age of 3 girls is 20 years and their ages are in the ratio 3:5.7. Find the
age of eldest girl.​

Answer 1

Answer:

Given that the ages of girls are in proportion 3:5:7

So, we can say that their ages are 3x,5x and 7x

Also, average age of 3 girls =20 years

⇒  

3

3x+5x+7x

​  

=20

⇒5x=20 i.e. x=4

∴ Age of youngest girl =3×4=12 years

Step-by-step explanation: