Question

2 years ago Dilip was 3 times as old as his son and 2 years hence ,twice his age will be equal to 5 times that of his son. Then the present age of Dilip is ??

Answer 1

let the age of dilip be 'x' and his son's age be 'y'
x-2=3(y-2)
x-2=3y-6
x-3y=-4⇒eq.1
2(x+2)=5(y+2)
2x+4=5y+10
2x-5y=6⇒eq.2
  

2x-6y=-8
-
2x-5y=6
------------
-y=-14
∴y=14yrs


x-3y=-4
x=3y-4
x=3(14)-4
x=42-4
x=38yrs
Ans ∴Dilip's age is 38 years

Answer 2

let Dilip's sons present age be x and his sons present age be y
2yrs ago
3(y-2)=x-2
3y-6=x-2
3y-x=4.
that is 2x-6y=-8. eq1
2yrs after
2(x+2)=5(y+2)
2x+4=5y+10
2x-5y=6. eq2
subtracting eq1 by eq2
2x-6y-2x+5y=-8-6
-y=-14
y=14
substituting y in eq2
2x-5(14)=6
2x=6+70
x=76/2
x=38
Hence Dilip's present age is 38 yrs .