Indian Institute of Foreign Trade 2012 Solved Paper

In a four-day period - Monday through Thursday - each of the following temporary office workers worked only one day, each a different day. Jai was scheduled to work on Monday, but he traded with Raj, who was originally scheduled to work on Wednesday. Farid traded with Kajal, who was originally scheduled to work on Thursday. Finally, Jai traded with Kajal. After all the switching was done, who worked on Tuesday?