Question

Four years ago,a father was thrice as old as his son.eight years hence,the

Answer 1

Let son's age 4 years ago be x years.

Thus, father's age at that time = 3x years.

After 8 years, son's age = (x+4) +8 = (x+12) years.

After 8 years, father's age = (3x+4)+8 = (3x+12) years

2(x+12)=3x+12

3x+12=2x+24

x=12

Present age of son = 12 + 4 = 16 
Present age of father = 40

Answer 2

Father's age be x
Son's age be y,
So, equation becomes,
3x-4 = y+8-4
3x-4 =y+4