1. swap two numbers without using third variable. 2. In the second round I was asked to write rest services with one to many relationships table. And run a cron job to display data in every 5 sec. 3. you have 9 bolls with similar weight and one more with slightly higher weight. So finally you have 10 balls. Now you have a balance scale, how can you find higher weight boll in minimum way. You will have to find 2 ways to do that. Ans. In worst case min weighting attempt is 2 and in worst case it is 3.