Mathematics for IGCSE & O level - Probability (Section 7 - No. 6)
A school has 100 students. 60 students take art, 40 take music, and 20 take both. If a student is selected at random, what is the probability they take *either* art or music?
0.8
0.4
0.6
0.2
Explication
Students taking either art or music: (60 + 40 - 20) = 80. Thus, 80/100 = 0.8