Recursions & Diagnostic Test

Over the weekend, I got the chance to start working on recursions on  Java Bat. I needed some external help, so I asked Uri T. for some help, but it was alright. I also got to work on 21 multiple choice from the Diagnostic Test in the Barron's Book. Easy to say, it was not that fun. I got 14 out of 21 right. It was actually quiet challenging and i tried looking at the explanation and it varied, for some I understood my mistake but for the others, it just confused me more so I left the questions. Especially questions 12, 14 and 20, I remain clueless about. I figured that I had problems with questions where there can be more then 2 possibilities to the answer like in question 12 and you have to verify each option one by one. I really need to practice on those questions. Also, question 18, which deals with the output being a numerical value, I could not comprehend the methods and thus I messed up. Overall, its was alright. Further I took a brake from the test and went to Java to work on Recursions while i was taking a brake. I think I understand string-recursion related problems well, so I should be able to do them smoothly.