Question

The ratio of the ages of two boys is 3:4. After 3 years, the ratio will be 4:5. The ratio of their ages after 21 years will be 10:11.
How old are they?​

Answer 1

Answer:

Step-by-step explanation:

Let the ages of boys be 3x and 4x years respectively.

According to the question,

After 3 years

3x + 3

=  

4

4x + 3 5

⇒  16x + 12 = 15x + 15

⇒  16x – 15x = 15 – 12

⇒  x = 3

∴  Required ratio after 21 years =  

3x + 21

4x + 21

3 × 3 + 21

=  

9 + 21

4 × 3 + 21 12 + 21

30

=  

10

30/33=10/11