How do I open a zip file?

Need to open a .zip file on my macbook but it's in three parts, how?

• The three files that wont open using Archive Utility look like this: Documents_PT1_ncedownloadind.ru.zip Documents_PT2_ncedownloadind.ru.zip Documents_PT3_ncedownloadind.ru.zip and have them stored in a folder called "folder" I keep getting a msgbox : Unable to unarchive "Documents_PT1_ncedownloadind.ru.zip" into "folder"(Error 1 - Operation not permitted.) its so annoying because i really want these files

• Answer:

  hee hee hee.......i love sudo.......there's 04 things you should be able to do.......... one: get stuffit expander, use that......if it needs a password it'll ask you for one. Second: check to see you have admin privelages to the folder, if so unlock it. Thirdly: if you don't want to go through the fourth option, move the files out of the folder unzip them and shove 'em back in. Fourth(will definitely work): open terminal and navigate to your destination folder using cd foldername to open folders... then type sudo unzip Documents_PT1_ncedownloadind.ru.zip; unzip Documents_PT2_ncedownloadind.ru.zip; unzip Documents_PT3_ncedownloadind.ru.zip NOTE: one space b/w unzip and the filename.........have fun and hope that helps