You were asked to "send it as a PDF," so you changed the end of the filename from ".docx" to ".pdf" and sent it. However, the ...

1How to view file name extensions for all files on a Mac 2How to view file name extensions for a individual file on a Mac The default setting for Mac OS is to not display a file's extension. For those ...

The Open Document Format (ODF) is a zip-compressed, Extensible Markup Language (XML)-based, Open Source file format for saving and exchanging text, spreadsheets, charts, graphics and presentations.

In the Mac OS it is possible to change the default program the operating system will use to open a file when you double-click on it. After you have changed this file association, though, you may want ...