Respuesta :

Answer:

8 yrs

Step-by-step explanation:

3(5+x)=31+x

15+3x=31+x

2x=16

x=2

Answer:

8 years.

Step-by-step explanation:

let after x years father's age is 3 times that of Rahul.

31+x=3(5+x)

31+x=15+3x

31-15=3x-x

2x=16

x=16/2=8