Question

The sum of father's age and twice the age of his son is 40. If we double the age of the father and add it to the age of his son's the sum is 65. Find present ages of father and son


40 and 10 years

25 and 5

30 and 5 years

30 and 10 years
..​

Answer 1

Answer:

Let the ages of father and his son be x and y respectively.

Case I:- The sum of the ages of father and his son is 65 years.

age of father + age of son = 65

⇒x+y=65⟶(i)

Case II:- After 5 years, fathers age will be twice the age of his son.

Age of father = 2 (age of son)

⇒x+5=2(y+5)

⇒x+5=2y+10

⇒x=2y+5⟶(ii)

From eq

n

(i)&(ii), we have

(2y+5)+y=65

⇒3y=65−5

⇒y=20

Substituting the value of y in eq

n

(i), we have

x+20=65

⇒x=45

Hence, the present age of father and son is 45 and 20 respectively and equation (i)&(ii) are the pair of linear equations in two variables.

Answer 2

Answer:

30 and 5 years

Step-by-step explanation:

I have solved this question using 2 variables