In a survey represented by a Venn diagram, the four disjoint regions representing cats are populated with the values 41, 39, 27, and 28. What is the total number of cats?

In a survey about news reading habits, the total number of residents reading only Newspaper is 25, watching only TV is 30, and listening to only Radio is 18. What is the total number of residents who rely on exactly ONE of these media sources to get news updates?

In a survey represented by a Venn diagram of three intersecting circles (Pastries, Ice Creams, and Chocolates), the intersection representing 'Pastries and Ice Creams but NOT Chocolates' contains the number 8. How many children prefer both pastries and ice creams but NOT chocolates?