A PHP Error was encountered

Severity: Notice

Message: Undefined offset: 0

Filename: controllers/Problemas.php

Line Number: 254

Backtrace:

File: /homepages/33/d349327298/htdocs/otraeducacion/matematicas/application/controllers/Problemas.php
Line: 254
Function: _error_handler

File: /homepages/33/d349327298/htdocs/otraeducacion/matematicas/index.php
Line: 317
Function: require_once