A Class XII student allegedly committed suicide by jumping into an irrigation well in Salem as she was reportedly upset at the prospects of not getting full marks in the maths exam.

The 17-year-old girl, studying at the Chinnappampatty Government Higher Secondary School in the district, was aiming to score full marks in the Mathematics paper. But the questions were tough and she was upset that she would not be able to score full marks in Maths in the exam conducted by the state board, police said.

She had scored 462 out of 500 in her Class X exam.

After writing the Maths exam on Friday, she informed her mother, a teacher, about the tough questions.

Police said she later wrote a letter to her parents stating that she was going to commit suicide as she could not get 100 per cent in Maths and jumped into a 75 feet-deep irrigation well last night.

The body was recovered this morning.