Dear Mai,
Here is the sample certifcation question and answer
http://www.sap-school.com/certificationquestionsQM.html
http://www.daypo.net/test-sap-quality-management-qm.html
http://www.daypo.net/sap-quality-management-qm-plm412.html
http://www.daypo.net/sap-qm-netweaver-solution-manager.html
http://www.daypo.net/test-sap-quality-management-qm-plm420.html
http://www.daypo.net/test-sap-quality-management-qm-plm415.html
please reward, if it is helpful