Twelve years ago, the ratio of the ages of Sohan and his father was 1:4. Three years from now, the ratio of their ages will be 2:5. Find the difference between their ages.Enter your response as an integer in the box given below​

Let father age is 7x

And son age is 2x

then after 15 year father age is 7x+15

After 15 year son age is 2x+15

⇒

2x+15

7x+15

=

1

2

⇒4x+30=7x+15

⇒4x−7x=15−30

⇒−3x=−15⇒x=5

Hence father present age=7×5=35

Son present age=2×5=10

difference of father and son age=35−10=25

So father age was 25 years when son was born