Question

The ages of hari and Henry are I ratio 5:7.four years from now the ratio of their will b 3:4. Find the present age

Answer 1

Let common factor be x
     Age of Hari and Henry are 5x and 7x respectively
     after four years their age will be (5x+4) and (7x+4)
As per question  (5x+4)/(7x+4) =3/4
                     ⇒  20x +16= 21x + 12
                      ⇒ x = 4 
Hari's age    5*4= 20
Henry's age  7*4= 28

Answer 2

Let hari's present age be 5x and henry's be 7x
Four years later:
hari's age = 5x + 4
henry's age = 7x + 4

A/Q
5x + 4       3
----------- = -----
7x + 4       4

=> 4 ( 5x + 4) = 3 ( 7x +4)
=> 20x + 16 = 21x + 12
=> 16- 12 = 21x - 20x
=> 4 = x
 therefore, present age of hari = 4 * 5 = 20
present age of henry = 4 * 7 = 28