Maria surveyed 80 students about which languages they study from French (FFF), Spanish (SSS), and German (GGG).
Every student studies at least one language.
15 students study all three languages.
10 students study French and Spanish but do not study German.
25 students study Spanish and German.
22 students study French and German.
50 students study Spanish.
5 students study only German.
Maria selects at random one of the 80 students.
Work out the probability that this student studies French.
