Sagar's present age is 16 years.
Let Sagar's age be S six years back. Kunal will be 6*S/ 5
Add 10 year to both the ages (6 years until present day and 4 more)
Sagar will be (S+10) and Kunal ((6*S/5)+10)
using the ratio Kunal : Sagar as 11:10
((6S/ 5) + 10) / (S+10) = 11/10
Solving this we get S = 10
This was 6 years back hence present age of Sagar will be 10+6 = 16