Is it permissible to pay a sum of money to the school in exchange for success in exams, after three years of study?

A school administration's demand for money in exchange for students' success is absolutely forbidden (haram), because it is an injustice to the successful student, and it is bribery and cheating if the student did not pass the exam successfully. However, if the student deserves to pass but is deprived of it unless a bribe is paid, then he may pay the amount, and the sin falls upon the recipient.