Question

Five years hence, the age of Jacob will be three times that of his son. Five years ago, Jacob's age was seven times that of his son. What are their present ages?

Answer 1

your answer is here

Answer 2

Answer:

Step-by-step explanation:

Given :-

Five years hence, the age of Jacob will be three times that of his son.

Five years ago, Jacob's age was seven times that of his son.

To Find :-

Their Present ages.

Solution :-

Let the present age of jacob and his son be x and y.

Five years hence

Jacob’s age = x + 5

His son’s age = y + 5

According to the Question

⇒ x + 5 = 3(y + 5)

⇒ x + 5 = 3y + 15

⇒ x = 3y + 15 – 5

⇒ x = 3y + 10 .....................(i)

Five years ago

Jacob’s age = x – 5

His son’s age = y – 5

According to the Question

⇒ x – 5 = 7(y – 5)

⇒ x – 5 = 7y – 35

⇒ x = 7y – 35 + 5

⇒ x = 7y – 30 ...................(ii)

Putting eq (i) x value in eq (ii) x value

⇒ 3y + 10 = 7y – 30

⇒ 3y + 10 + 30 = 7y

⇒ 7y – 3y = 40

⇒ 4y = 40

⇒ y = 40/4

⇒ y = 10

Putting y value in Eq (i)

⇒ x = 3y + 10

⇒ x = 3 x 10 + 10

⇒ x = 40

Hence, Jacob’s age = 40 years and son’s age = 10 years