I downloaded Qt 5 under Linux both 64bit and 32bit and the extension was *.run. I tried all these and it just doesn't work.
sh qt_linux.run
this error: qt_linux.run: qt_linux.run: cannot execute binary file
or
chmod +x qt_linux.run ./qt_linux.run
this error: ./qt_linux.run: /usr/lib64/libstdc++.so.6: version `GLIBCXX_3.4.15' not found (required by ./qt_linux.run)
or
* double click it
this error: nothing happens
or
* right click it>properties
* check the box next to executable
* double click it
this error: nothing happens