How many people in the group, speak both French and German?

Question

A group of 110 people touring Europe includes 51 people who speak French, 59 who speak German, and 22 who speak neither language. How many people in the group,
speak both French and German?

Answer 1

110 people

22 speak neither French nor German

110-22=88

88 people speak French, or German, or both languages

51 speak French and 59 speak German

51+59=110

but only 88 people speak a language

110-88=22 people speak both French and German