Five years hence, the age of jacob will be three times of his son. five years ago, jacob's age was seven times that of his son. What are their present ages?
Answers
Answer:
Given :-
The age of Jacob will be three times that of his son.
Solution :-
Let the present age of Jacob be be x year
And the present Age of his son be be y year
Five years Ago
Jacob’s age will be = x + 5 year
Age of his son will be = y + 5 year
According to the Question,
⇒ x + 5 = 3(y + 5)
Adding 5 to both side,
⇒ x = 3y + 15 - 5
⇒ x = 3y + 10 … (i)
Five years ago,
Jacob’s age= x - 5 year
His son’s age = y - 5 year
Jacob’s age was seven times that of his son
⇒ x - 5 = 7(y - 5)
Putting the value of x from equation (i) we get
⇒ 3y + 10 - 5 = 7y - 35
⇒ 3y + 5 = 7y – 35
⇒ 3y - 7y = - 35 - 5
⇒ -4y = - 40
⇒ y = - 40/-4
⇒ y = 10 year
Putting the value of y in equation we get
⇒ x = 3 × 10 + 10
⇒ x = 40 years
Present age of Jacob = 40 years,
Present age of his son = 10 years.
Answer:
Let five years ago Jacob's son age = x
So five years ago Jacob's age = 7x
So present age of Jacob's son age = x + 5
So present age of Jacob' age = 7x + 5
So five years after Jacob's son age = x + 5 + 5= x + 10
So five years after Jacob's age = 7x + 5 + 5= 7x + 10
By the given condition
7x + 10 = 3(x+10)
➙ 7x+ 10 = 3x + 30
➙ 7x - 3x = 30 - 10
➙ 4x = 20
➙ x = 5
So present age of Jacob's son age = 5 + 5 = 10 years
& present age of Jacob' age = 35 + 5 = 40 years