Mathematics for IGCSE & O level - Probability (Section 6 - No. 29)
If a train arrives on time with a probability of 0.7, what's the probability the train will be late on three consecutive days?
0.21
0.3
0.027
0.009
คำอธิบาย
Probability of being late is 1 - 0.7 = 0.3. For three consecutive days: 0.3 * 0.3 * 0.3 = 0.027