Five years ago a man was seven times as old as his son. Five years hence, the father will be three times as old as his son. Find their present ages
Answers
Step-by-step explanation:
Firstly we will assume that present age of man is x years and present age of his son be equals to y years .
Now , 5 years ago,
Age of man = (x-5)years.
Age of son=(y-5) .
As given that "five years ago the man was 7 times as old as his son"
lt gives a linear equation in two variables in form of x and y.
Also,
five years hence ,
Age of man =(x+5)years
&
Age of son =(y+5)years .
Given that
"5 years hence the man will be 3 times as old as his son"
It will give second linear equation in two variables in form of x & y.
After solving these two equations simultaneously, we can calculate the values of x & y which are their present ages.
Let y be the age of son.
Let 7y be the age of father.
y + 5 , 7y + 5 are the present ages
= y + 10 future age of son.
7y + 10 is father.
= (7y + 10 = 3) (y + 10)
= (y = 5)
= (7y = 35)
(y + 5 = 5 + 5 = 10)
.•. 10 years is age of son and
(7y + 5 = 7) ×( 5 + 5 = 40) .•. 40 is age of father.
Hope it helps!