CAIE A-Level Mathematics AS 5.3.2 Probability Rules Questions
Practise calculating conditional, joint and complementary probabilities for dependent events.
- Syllabus
- 2028–2030
- Course
- Mathematics 9709
- Level
- AS
Practise calculating conditional, joint and complementary probabilities for dependent events.
The residents of Mahjing were asked to classify their local bus service:
- 25 % of residents classified their service as good.
- 60 % of residents classified their service as satisfactory.
- 15 % of residents classified their service as poor.
Three residents of Mahjing are selected at random.
Find the probability that one resident classified the bus service as good, one as satisfactory and one as poor.
The three classifications can occur in 3!=6 orders. Hence,
P=0.25(0.6)(0.15)×6=0.135.