Question

Ratio of present ages of two persons a and b is 3:2 and after four years ratio of their age (b :



a.Become 7:10. Then find the present age of b?

Answer 1

Solutions :-

Given :
Ratio of present ages of two persons a and b is 3 : 2
After four years ratio of their age b : a become 7 : 10. So a : b = 10 : 7

Let the present age of two persons a and b be 3x and 2x respectively.


According to the question,

=> (3x + 4)/(2x + 4) = 10/7
=> 7(3x + 4) = 10(2x + 4)
=> 21x + 28 = 20x + 40
=> 21x - 20x = 40 - 28
=> x = 12


Therefore,
Age of b = 2x = 2 × 12 = 24 years

Answer 2

$<b>$
Solution:-

Let the Ratio of Age of A & B be 3x : 2x.

After 4 years,

The Ratio of Age of A & B =

$= > \frac{3x + 4}{2x + 4} = \frac{10}{7} \\ \\ = > 7(3x + 4) = 10(2x + 4) \\ \\ = > 21x + 28 = 20x + 40 \\ \\ = > 21x - 20x = 40 - 28 \\ \\ = > x = 12.$

Hence,

$\boxed{Age of A = 3x = 36 years.}$

& $\boxed{Age of B = 2x = 24 years.}$