I. Roshan, R = 25 years.
II. Ravi, Ra = 30 years.
Explanation:
Let the age of Roshan be R
Let the ages of Ravi be Ra
Given the following data;
R + Ra = 55
Ratio of their ages = 5:6 = 5 + 6 = 11
To find the age of R;
![R = \frac {5}{11} * 55](/tpl/images/1211/7069/3c6e4.png)
![R = \frac {275}{11}](/tpl/images/1211/7069/c371a.png)
Roshan, R = 25 years.
To find the age of Ra;
![R = \frac {6}{11} * 55](/tpl/images/1211/7069/6d45f.png)
![R = \frac {330}{11}](/tpl/images/1211/7069/e6606.png)
Ravi, Ra = 30 years.