The average age of 3 girls is 20 years and their ages are in proportion 3 - 5 - 7- the age of youngest girl is - 8 years 3 months6 years 8 months12 years20 years

Question

Toppr Admin · Accepted Answer

Given that the ages of girls are in proportion $3 : 5 : 7$
So, we can say that their ages are $3 x, 5 x$ and $7 x$

Also, average age of $3$ girls $= 20$ years
$\Rightarrow \frac{3 x + 5 x + 7 x}{3} = 20$

$\Rightarrow 5 x = 20$ i.e. $x = 4$
$∴$ Age of youngest girl $= 3 \times 4 = 12$ years

The average age of 3 girls is 20 years and their ages are in proportion 3:5:7, the age of youngest girl is ___. 8 years 3 months6 years 8 months12 years20 years

Given that the ages of girls are in proportion 3:5:7So, we can say that their ages are 3x,5x and 7xAlso, average age of 3 girls =20 years⇒3x+5x+7x3=20⇒5x=20 i.e. x=4∴ Age of youngest girl =3×4=12 years

The average age of $3$ girls is $20$ years and their ages are in proportion $3 : 5 : 7,$ the age of youngest girl is ___.
$8$ years $3$ months
$6$ years $8$ months
$12$ years
$20$ years

Given that the ages of girls are in proportion $3 : 5 : 7$
So, we can say that their ages are $3 x, 5 x$ and $7 x$

Also, average age of $3$ girls $= 20$ years
$\Rightarrow \frac{3 x + 5 x + 7 x}{3} = 20$

$\Rightarrow 5 x = 20$ i.e. $x = 4$
$∴$ Age of youngest girl $= 3 \times 4 = 12$ years