Who sits third to the right of the person, who likes Coca cola in the row arrangement?   

First read all the conditions which are given in the question. Then start with circular arrangement from the given conditions. After that carry only that conditions which is related to circular arrangement and try to complete circular arrangement. After completing circular arrangement from the given conditions, you should try to start linear arrangement and follow given conditions. Then you will see there are more possibilities that can be drawn for the linear arrangement, but if you will follow conditions carefully then most possibilities will neglect one by one except one. That will be our final linear arrangement. At last you will see only one linear arrangement and one circular arrangement which will follow all the given conditions.