Luck element is needed. It's not about difficulty, but the complete random nature of the questions. You may be asked the citation of a case which you have never heard of in your life. Some of the questions may have all 4 wrong options. Stick to going through one good guidebook, the basic textbook for each of the subjects, and then solve as many mocks as you can. I was lucky to have managed to clear it the first time around, but honestly I don't know what I had done right.