The deceased was identified as Trishna Rani, daughter of Dulal Roy and student of Mahiganj High School.
Sirajul Islam, acting headmaster of the school said that Trishna, a student of commerce group, came to school today to attend farewell programme and received her admit card.
After receiving her admit card, she found in her admit card that the group was humanities.
According to family source, after returning home Trishna went to her room and hanged herself with her scarf.
Shakerina Begum, upazila secondary education officer, said that if the girl received the admit car earlier, the untoward situation would not be happened.
Necessary steps will be taken after investing the issue that why farewell programme was arranged a day before examination, she said.