Question

after 12 years I shall be 3 times as old as I was 4 years ago find my present age​

Answer 1

Let the present age be 'x'

After 12 years I shall be 3 times as old as I was 4 years ago.

After 12 yrs age becomes ( x + 12 )yrs and before 4 yrs age was ( x - 4 ) yrs.

According to the question ,

$x + 12 = 3(x - 4) \\ \\ \implies x + 12 = 3x - 12\\ \\ \implies x - 3x = - 12 - 12 \\ \\ \\ \implies - 2x = - 24 \\ \\ \\ \implies \boxed {x =12 }$

Therefore, the present age of him is 12yrs.

VERIFICATION :-

LHS = x + 12 = 12 + 12 = 24

RHS = 3 ( x - 4 ) = 3 ( 8) = 24

LHS = RHS , our answer is correct !

Answer 2

Let Age of Person 4 years ago=x

yearsThen Present age of Person=(x+4) years.

After 12 years His Age Will be

(x+4+12)=(x+16) years

Now Question Saying

His Age After 12 years(x +16)is 3×Age 4 years ago(x)

Means

Age after 12 years=3×age 4 years ago

A/Q

x+16=3x

16=3x-x

16=2x

x=16/2

x=8

Present age=x+4=8+4=12 years

CHECK

Given Equation

x+16=3x

x=8

8+16=3×8

24=24

Hence LHS=RHS

So,

Present Age=12 years