Final answer:
The main principle that the World Bank and IMF had in common is economic stability. They were created to guarantee international economic stability and provide financial assistance to countries in need.
Step-by-step explanation:
The main principle that the two organizations formed in 1944, the World Bank and the International Monetary Fund (IMF), had in common was economic stability. These institutions were created with the goal of guaranteeing international economic stability and rebuilding Europe after World War II. The IMF was established to provide financial assistance to countries in need and help them improve their economies, while the World Bank focused on providing loans and support for development projects around the world.