This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Look for compile time errors in the questions before you follow the logic of the question. There might be a missing public while overriding method of an interface or the signature of the main method might be wrong.