After Six years , a man's age will be three times the age of his son and three years ago he was nine times of his son's age. Find the present age of the man. [3 MARKS]
Concept : 1 Mark
Application : 1 Mark
Calculation : 1 Mark
Let the present age of the man be x and that of the son be y
After six years their age is
x+6,y+6
According to given condition,
x+6=3y+18……(i)
Three years ago their age is
x−3,y−3
According to given condition,
x−3=9y–27……(ii)
On solving (i) and (ii) we get,
x=3y+18−6⇒x=3y+12
Substituting value of x in (ii)
x−3=9y–27
3y+12−3=9y–27
3y+9=9y–27⇒y=6
Now , x=3y+12
x=3(6)+12⇒x=30
x=30,y=6
∴ Present age of father is 30 years and sons age is 6 year.