Single-sex schools are a common phenomena. Most of the convents and religious schools in middle ages throughout the world seperated classrooms by gender. Convents in many European countries, Hindu religious schools in India and confucian schools in China, had this practice of gender segregation at schools. However, during the 19th century, co-education schools became prominent and are now a default mode of education. However, regarding the benefits of both, there are some disagreements.