Question

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

Answer 1

Let the common ratio be x.
So, age of Hari = 5x
and age of Harry = 7x

After 4 years,
age of Hari = 5x+4
and age of Harry = 7x+4

According to question,
(5x+4)/(7x+4) = 3/4
4(5x+4) = 3(7x+4)
20x + 16 = 21x + 12
x = 4

So,
present age of Hari = 5x = 5×4 = 20
and present age of Harry = 7x = 7×4= 28

Answer 2

(5x+4)/(7x+4)=3/4
20x+16=21x+12
16-12=21x-20x
4=x
5x=4×5
=20
7x=4×7
=28