Soru

A specialty coffee roastery surveyed $200$ customers to determine their preferences among three origin beans: Ethiopian ($E$), Colombian ($C$), and Guatemalan ($G$). Every customer surveyed preferred at least one of the three origins. The survey revealed that $105$ customers preferred Ethiopian, $90$ preferred Colombian, and $85$ preferred Guatemalan. Additionally, $35$ customers preferred both Ethiopian and Colombian, $30$ preferred both Colombian and Guatemalan, and $40$ preferred both Ethiopian and Guatemalan. How many customers preferred all three origin beans?