Question

5 years ago a man was 7 times as old as his son . After 5 years he will be thrice as old as his son . Find their present afes

Answer 1

Answer:

Let the present ages of man and his son be X and Y years respectively.

Step-by-step explanation:

5 years ago,‌

Man's age = (x-5) years

And son's age= (y-5) years.

By question,

(x-5)= 7(y-5).............(1)

Or,x-5=7y-35

Or,x-5+35-7y=0

Or,x-7y+30=0.........(A)

Again,‌ by question

After 5 years,

(X+5)=3(y+5).............(2)

Or, x+5-3y-15=0

Or,x-3y-10=0...........(B)

Solving equations AandB we get

-4y+40=0. {Subtracting B From A}

Or 4y =40

Therefore y= 10 years

Now, X= 3y+ 10. (From B)

= 3*10+10

=40 years.

Answer 2

Answer:

Let Five years ago the age of son be x years and age of father be 7x years

Let Five years ago the age of son be x years and age of father be 7x yearsPresent age of son =x+5

Let Five years ago the age of son be x years and age of father be 7x yearsPresent age of son =x+5Present age of father =7x+5

Let Five years ago the age of son be x years and age of father be 7x yearsPresent age of son =x+5Present age of father =7x+55 years later their age will (x+10) and (7x+10)

Let Five years ago the age of son be x years and age of father be 7x yearsPresent age of son =x+5Present age of father =7x+55 years later their age will (x+10) and (7x+10)∴7x+10=3(x+10)

Let Five years ago the age of son be x years and age of father be 7x yearsPresent age of son =x+5Present age of father =7x+55 years later their age will (x+10) and (7x+10)∴7x+10=3(x+10)7x−3x=20

Let Five years ago the age of son be x years and age of father be 7x yearsPresent age of son =x+5Present age of father =7x+55 years later their age will (x+10) and (7x+10)∴7x+10=3(x+10)7x−3x=204x=20

Let Five years ago the age of son be x years and age of father be 7x yearsPresent age of son =x+5Present age of father =7x+55 years later their age will (x+10) and (7x+10)∴7x+10=3(x+10)7x−3x=204x=20x=5

Let Five years ago the age of son be x years and age of father be 7x yearsPresent age of son =x+5Present age of father =7x+55 years later their age will (x+10) and (7x+10)∴7x+10=3(x+10)7x−3x=204x=20x=5So, the present age of son=x+5=5+5=10years

Let Five years ago the age of son be x years and age of father be 7x yearsPresent age of son =x+5Present age of father =7x+55 years later their age will (x+10) and (7x+10)∴7x+10=3(x+10)7x−3x=204x=20x=5So, the present age of son=x+5=5+5=10yearsand the present age of father=7x+5=35+5=40years