The sum of the ages of father and his son before 5 year was 56. When the son was 5 years old his father was 33 find the present age of father? A. 42 B. 45 C. 53 D. 47

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Answer:

Let x years be the present age of the father, then the present age of the son will be (45−x) years.

Five years ago, the age of father was (x−5) years and that of son was (45−x−5)=(40−x) years.

As, five years ago, the product of ages was 124.

(x−5)(40−x)=124

⇒x

2

−45x+324=0

⇒(x−9)(x−36)=0

⇒x=9,x=36

When x=36, the age of father is 36 and the age of son is 9 years.

When x=36, the age of the father is 9 years and the age of the son is 36 years, which cannot be possible, so the present age of father is 36 years and that of the son is 9 years.

Answer:Let x years be the present age of the father, then the present age of the son will be (45−x) years.

Five years ago, the age of father was (x−5) years and that of son was (45−x−5)=(40−x) years.

As, five years ago, the product of ages was 124.

(x−5)(40−x)=124

⇒x

2

−45x+324=0

⇒(x−9)(x−36)=0

⇒x=9,x=36

When x=36, the age of father is 36 and the age of son is 9 years.

When x=36, the age of the father is 9 years and the age of the son is 36 years, which cannot be possible, so the present age of father is 36 years and that of the son is 9 years.