ICSE

First of all, You have not mentioned your stream in question, so I assumed it to be Science. However, When you'll study old papers you'll observe a trend in questions, there is nothing new, every year same questions pop up on your final boards sometimes even without changing values like in Maths and Physics numerical. You can predict your paper, by studying previous year's papers, and I prefer to take a guidebook with solutions because that will tell you, what is needed in an answer and how you have to pen it down on your sheet. Also, some topics are almost there every damn year like a reaction from SN1 of SN2 or a detailed explanation of gamete production in male and female angiosperms. But the Central Board of Secondary Education boards is all about knowing the question thoroughly from previous year Sets.