@Harshit_Gupta Don't fear that what will happen if any such thing happens in exam what will you do. Because if any question will be new for you, it's going to be new for everyone. What you should be scared of is if a question which you already solved comes in exam and you are unable to solve it. To avoid any such situation, mark every question which you are unable to solve at first attempt. Make sure you are able to solve it next time or atleast are better in solving the steps compared to last time.