The problem provides us with the following information:
- The ratio of the ages of two persons is 5:7.
- Eighteen years ago, their ages were in the ratio of 8:13.

Let's solve the problem step by step:

1. Assign variables:
- Let's assume the present age of the first person is 5x.
- Therefore, the present age of the second person would be 7x.

2. Calculate their ages 18 years ago:
- The age of the first person 18 years ago would be 5x - 18.
- Similarly, the age of the second person 18 years ago would be 7x - 18.

3. Given that 18 years ago, their ages were in the ratio of 8:13, we can form the equation:
(5x - 18) / (7x - 18) = 8 / 13

4. Solve the equation:
- Cross-multiply to eliminate the fractions: 13(5x - 18) = 8(7x - 18)
- Simplify: 65x - 234 = 56x - 144
- Combine like terms: 65x - 56x = 234 - 144
- Solve for x: 9x = 90
- Divide both sides by 9: x = 10

5. Calculate their present ages:
- The present age of the first person is 5x = 5(10) = 50 years.
- The present age of the second person is 7x = 7(10) = 70 years.

Thus, the present ages of the two persons are 50 years and 70 years, respectively.

In summary:
- First person's present age: 50 years
- Second person's present age: 70 years

I think present age = 50:70

am I right