Question

20 years ago the age of a father was four times the age of his son. After four years from now the age of father will be double that of the son. Find the present ages of the
father and son.

Answer with full Explantaion!

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Answer 1

Given :

• 20 years ago the age of a father was four times the age of his son.
• After four years from now the age of father will bprese double that of the son.

To Find :

• The present age of the father and son ?

Solution :

• Let us assume :

➣ The present age of son be x.

➣ And the present age of father be y.

20 years ago :

• Son's age = x - 20
• Father's age = y - 20

According to the question :

➣ 4(x - 20) = y - 20

➣ 4x - 80 = y - 20

➣ 4x - 80 + 20 = y

➣ 4x - 60 = y (i)

After four years :

• Son's age = x + 4
• Father's age = y + 4

According to the question :

➣ 2(x + 4) = y + 4

➣ 2x + 8 = y + 4

➣ 2x + 8 - 4 = y

➣ 2x + 4 = y (ii)

Comparing eqⁿ (i) & eqⁿ (ii).

➣ 4x - 60 = 2x + 4

➣ 4x - 2x = 4 + 60

➣ 2x = 64

➣ x = 64/2

➣ x = 32

Putting the value of x in eqⁿ (ii).

➣ 2x + 4 = y

➣ 2(32) + 4 = y

➣ 64 + 4 = y

➣ 68 = y

➣ y = 68

Hence,

• The present age of :

➣ Son = 32 years

➣ Father = 68 years.

Answer 2

A N S W E R :

• The present age of :

➣ Son = 32 years

➣ Father = 68 years.