Question

the ages of Rahul and haroon are in the ratio of 5:7. 4 years later the sum of the ages will be 56 years what is their present age

Answer 1

let the ratio be 5x and 7x respectively.
4 years later
the age of rahul= 5x -4
the age of haroon=7x-4 
according to the question,
5x-4 +7x-4=56
12x-8=56
12x=56+8
12x=  64
x=64/12

Answer 2

rahul=5x
haroon=7x
after 4 years
rahul=5x+4
haroon=7x+4
total=5x+4+7x+4 = 56
12x+8=56
12x=56-8
12x=48
x=48/12
x=4
present of rahul=5*4 = 20
present age of haroon=7*4=28