BHOPAL : The question paper of higher secondary supplementary examination conducted by MP Board of Secondary Education was changed due to mistake in coding by paper setters on Monday. Board officials said printers put question paper of mathematics subject of XI standard on the place of question paper of XII standard in the same subject and examination centre in-charges knew about it when they opened envelops in the morning. “It happened across the state leading to postponing of examination,” said board officials. The paper of XII standard examination will now be held on July 14.