Viewing Questionnaire responses
If you click on a questionnaire on a course to which you have editing access, you recieve the option to View 'n' responses in the top-right corner, where 'n' refers to the number of completed surveys. Clicking this will take you to the Survey Reports page which gives you a graphical (bar chart) and numerical breakdown of responses using both total and percentage results.
There is no mechanism to automatically make the results available to students who have taken the questionnaire. You could however save the displayed results as an HTML file and upload that as a resource.
At the bottom of this page you have the option to switch your view between individual responses and all responses and/or download a CSV version of the responses. In the CSV file fields are identified by the name you entered when creating them.