Question

8. Present age of Rahul and kiran are in the ratio

5:4. The ratio of their ages will be 6:5 after
5 years.Find kiran's present age.
20 years
25 years
30 years
15 years​

Answer 1

20 years

Explanation:

Given the ratio of their ages = 5 : 4 = 5x : 4x ( x is a multiplier )

Then in 5 years

5x + 5 : 4x + 5 = 6 : 5 , that is

`(5x+5)/(4x+5)` =
`(6)/(5)` ( cross- multiply )

5(5x + 5) = 6(4x + 5) ← distribute parenthesis on both sides

25x + 25 = 24x + 30 ( subtract 24x from both sides )

x + 25 = 30 ( subtract 25 from both sides )

x = 5

Thus

Kiran's age is 4x = 4 × 5 = 20