Question

A father is three times as old as his son. after 15 years, he will be twice as old as his son. what are their present ages.​

Answer 1

Answer:

Their parents age is 45 three times as old as his son.

Answer 2

Answer:

• Son's present age = 15 years
• Father's present age = 45 years

                                                                                                                             

Step-by-step explanation:

• Present age :-

        => Let the son's present age be = x years.

                Father is three times as old as  his son. Therefore,

         => Father's present age = 3x years.

• After 15 years :-

        => Son's age = (x + 15) years

                  Father becomes twice as old as his son.

        => Father's age = 2(x + 15) years

--  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  --  

Difference between the ages of father and son always remains same.

That is,

Father's present age - Son's present age =

                                   Fathers age after 15 years - Son's age after 15 years

=> (3x - x) = (2[x + 15] - [x + 15])

=> 2x = (2x + 30 - x - 15)

=> 2x = x + 15

=> 2x - x = 15

=> x = 15

Therefore, the son's present age = 15 years.

Father's present age = 3x = 3 × 15

= 45 years