In the IIT JAM Mathematics Exam, the marks allotted for each question are not mentioned on the question paper. Here's an explanation of why:

Importance of Not Mentioning Marks:
The IIT JAM Mathematics Exam follows a marking scheme known as the Multiple Choice Questions (MCQs) pattern. In this pattern, the examiners do not mention the marks allotted for each question on the question paper. This is done intentionally to ensure fairness and avoid any bias while evaluating the answer scripts.

Reasons for Not Mentioning Marks:
1. Equal Weightage: By not mentioning the marks, it ensures that each question carries equal weightage in the examination. This means that all questions are equally important and need to be answered carefully.

2. Focus on Understanding: The primary objective of the IIT JAM Mathematics Exam is to assess the candidate's understanding and knowledge of the subject. By not mentioning the marks, it encourages the candidates to focus on understanding the concepts and solving the problems effectively, rather than just attempting questions to gain maximum marks.

3. Elimination of Random Guessing: Not mentioning the marks also discourages candidates from randomly guessing the answers. Since they are not aware of the marks assigned to a particular question, they are more likely to answer based on their knowledge and understanding of the subject rather than relying on luck.

Marking Scheme:
In the IIT JAM Mathematics Exam, each question usually has four options, out of which only one option is correct. For each correct answer, candidates are awarded positive marks, while for each incorrect answer, negative marks are deducted as per the prescribed scheme. The marking scheme may vary from year to year, and it is mentioned in the examination guidelines.

Conclusion:
In conclusion, the marks allotted for each question are not mentioned on the question paper in the IIT JAM Mathematics Exam. This is to ensure fairness, equal weightage to all questions, and to encourage candidates to focus on understanding the subject rather than just attempting questions for the sake of marks. The marking scheme, including positive and negative markings, is mentioned in the examination guidelines provided to the candidates.