Question

Four years ago, the father's age was three times the age of his son. The total of the age of the father and the son after four years will be $64$ years. What is the father's age at present?

• A. $32$ years
• B. $36$ years
• C. $44$ years
• D. $40$ years

Answer 1

The correct option is D $40$ years

fathers present age $=x$ years.

sons present age $=y$ years.

four years ago, fathers age $=3\times$ sons age.

$(x-4)=(y-4)\times 3$

$x=3y-8$.....(i)

after 4 years, fathers age$+$ sons age $=64$

$x+4+y+4=64$

$x+y=56$.....(ii)

solve for $x$

$x=3\times 56-3x-8$

$4x=160$

$x=40$ years

D is correct.