Ans: Yes, you can appear for the IMO exams even though you have appeared previously. Thousands of students reappear for the exam to improve their rankings. IMO is a highly competitive exam and thus students are encouraged not to lose hope and keep trying even though they have appeared previously and could not perform as per their expectations. Participating in the International Mathematics Olympiad will only boost their intellect and confidence and provide them with a window to how competitive exams in advanced classes look like.