Final answer:
An individual who fails a qualifying examination for LP-gas activities must immediately cease performing related activities such as installation, maintenance, or repairs, as they no longer meet the required safety and knowledge standards.
Step-by-step explanation:
If an individual fails a qualifying examination for LP-gas activities, that person must immediately cease performing any LP-gas related activities.
These activities could include, but may not be limited to, gas system installation, operation, maintenance, and repairs. Failing the qualifying examination means that the individual no longer meets the minimum safety and knowledge requirements set forth by regulating bodies to carry out these duties safely and effectively.
Therefore, until the individual retakes and passes the examination, they are not certified to work with LP-gas.