?

How to Find the Present Age of 2 People Using the Given Age Ratios?

By Team Aakash Byju's | 24th November 2022

The ages of Hari and Harry are in a ratio of 5:7. Four years from now the ratio of their ages will be 3:4. Find their present ages.

It is given that the ratio of the present ages of Hari and Harry is 5:7. So, let 5x and 7x be the ages of Hari and Harry respectively.

For any value of  x, Hari’s age = 5x Harry’s age = 7x

After 4 years, their ages are in the ratio 3:4.

=> Hari’s age after 4 years from now = 5x+4 => Harry’s age after 4 years from now = 7x+4 => (5x+4) : (7x+4) = 3 : 4

Let us solve this equation as follows:

5x + 4

7x + 4

=

3

4

=> 4 (5x+4) = 3 (7x+4) => 20x + 16 = 21x + 12

Combine the like terms and solve for x.

=> 21x - 20x  =  16 - 12 => x = 4

Now, find the present age of Hari and Harry using the value of x.

Hari’s age = 5x = 5(4)                                  = 20 years Harry’s age = 7x = 7(4)                                     = 28 years.