Mathematics for IGCSE & O level - Probability (Section 1 - No. 6)
In a class of 25 students, 10 students are wearing glasses. If a student is selected at random, what is the probability they are *not* wearing glasses?
2/5
3/5
1/10
1/25
คำอธิบาย
10 wear glasses. 15 do not. 15/25 = 3/5.