i want to know the resposibilities of an admintrative assistant

Basic duties of an admin assistant - filing (creating files and putting them away), typing documents, answer phones, creating documents (word, excel, etc), researching topics, creating protocol. On top of such duties there may be other duties that the company may want you to be able to perform such as data entry, and database management. There quite often is a requirement for WPM typed. If you are interviewing for an administrative assistant position you should have a detailed conversation with whoever is hiring you to ensure that you have the correct skill set for what they are looking for and any jobs they may have in line for you to work on in the future if you are hired.