You can use 7zip or winrar for open rar and zip files for free.
http://www.7-zip.org/download.html
https://www.rarlab.com/download.htm
The Microsoft Office files (doc, docx, xls, xlsx, ppt, pptx, etc.) can be opened with Microsoft Word, PowerPoint, Excel etc. Go to this link to download a 60 day trial version:http://office.microsoft.com/en-us/try/
For problems regarding different versions compatibility go here: http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=3
For all your queries in the stated fields, that is ECONOMICS, BUSINESS FINANCE, ACCOUNTING, STATISTICS, HISTORY, MATHEMATICS and PSYCHOLOGY, feel free to consult me for thorough, quality and well-researched solutions.
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Regards,
AcerHands