Long answer·Hard exam skill (4/5)·No calculatorNeeds mentor review
Difficulty guide
The label describes the problem, not your ability.
1/5 - Foundational
Warm-up setup; checks one basic idea.
2/5 - Routine exam skill
Normal syllabus skill; usually one main rule or interpretation.
3/5 - Standard multi-step
Exam-style problem with multiple steps or a common trap.
4/5 - Hard exam skill
High-end exam problem; combines methods carefully.
5/5 - Challenge
Stretch problem beyond normal exam pressure.
Question
A shop receives items from suppliers as shown in the table.
Total: 4 marks
(a) Find the probability that a randomly selected item is defective. (2 marks)
(b) Find the probability that the item is not defective. (1 mark)
(c) Find the probability that the item came from supplier and is defective. (1 mark)
Something wrong with this item?