Question

A father's age is 4 times as that of his son's age. in 5 years time, the father will be 3 times as old as his son. what are their present ages?​

Answer 1

Answer:

present age of son = 10

present age of father = 40

Step-by-step explanation:

Let, present age of son be 'x'

present age of father be 'y'

y = 4x→ equation ( i )

After five years,

Son's age = x + 5

father's age = y + 5

According to Question,

$y + 5 = 3(x + 5)$

Put the value of y from equation ( i )

$4x + 5 = 3(x + 5)$

Distribute 3 through the parentheses

$4x + 5 = 3x + 15$

Move variable to L.H.S and change it's sign

Similarly, Move constant to R.H.S. and change its sign

$4x - 3x = 15 - 5$

Collect like terms

$x = 15 - 5$

Calculate the difference

$x = 10$

Now, put the value of X in equation ( i ) in order to find the present age of father

$y = 4x$

plug the value of X

$= 4 \times 10$

Calculate the product

$= 40$

Therefore,

Present age of son = 10

present age of father = 40

Hope this helps..

Best regards!!