Question

10 years ago A was 1 3rd of B's age .If the ratio of the present ages of A and B is 4:7,what is the total sum of their ages after five years?

Answer 1

Answer:

It is given that, the ratio of the present ages of A and B is 4:7.

Thus,

Let the present age of A be 4x years

and the present age of B be 7x years.

Thus, we have,

Age of A 10 years ago = (4x - 10) years

Age of B 10 years ago = (7x - 10) years

Now,

According to the question;

10 years ago A was 1/3 rd of B's age.

=> (4x - 10) = (1/3)•(7x - 10)

=> (4x - 10) = (7x - 10)/3

=> 3•(4x - 10) = (7x - 10)

=> 12x - 30 = 7x - 10

=> 12x - 7x = 30 - 10

=> 5x = 20

=> x = 20/5

=> x = 4

Thus,

The present age of A =4x=4•4=16 years

and present age of B =7x=7•4=28 years

After 5 years ;

Age of A = 16 + 5 = 21 years

Age of B = 28 + 5 = 33 years.

Hence, the total sum of their ages after five years is (21 + 33) years.

ie, 54 years.