How to run 32-bit applications on 64-bit Ubuntu 16.04

To run a 32-bit executable file (for example Android SDK tools) on a 64-bit multi-architecture Ubuntu system, you have to add the i386 architecture and install the three library packages libc6:i386, libncurses5:i386, and libstdc++6:i386: sudo dpkg --add-architecture i386

Then: sudo apt-get update
sudo apt-get install libc6:i386 libncurses5:i386 libstdc++6:i386

After these steps, you should be able to run the 32-bit application: ./example32bitprogram