In 111 centres across the state, 31,351 students, including 15,152 girls from 236 higher secondary schools, appeared for the exams. Last year, around 36,000 students had appeared for the examinations. COHSEM chairman Takhellambam Ojit Singh said the exams are scheduled to end on March 23. Of the total number of centres, 36 are in the ten hill districts and 75 are in the six valley districts.