4MA1/2HR Jun 2018, Question 16: Tree Diagrams for Dependent Events
Pearson Edexcel International GCSE Mathematics A 4MA1 · Paper 2HR (Higher) · Calculator · 4 marks
اقرأ هذا الحل مشروحاً بالعربي ←
The question, in short
Bag has 8 counters numbered 1,1,2,4,4,5,5,5. Three are drawn at random and their numbers summed. Find the probability the total is odd.
Summarised in our own words. Use the official paper for the exact wording and any diagrams.
Solution · 4 marks
- 1Odd counters: 1, 1, 5, 5, 5 (5 of them); even: 2, 4, 4 (3 of them)
- 2Total is odd with 3 odds, or 1 odd and 2 evens
- 3P(odd, odd, odd) = 5/8 × 4/7 × 3/6 = 60/336
- 4P(1 odd, 2 evens) = 3 × (5/8 × 3/7 × 2/6) = 90/336
- 5P(odd total) = 150/336 = 25/56
Answer25/56
Stuck on a step? Read the free lesson: Tree Diagrams for Dependent Events
Practise more tree diagrams for dependent events questions
Real 4MA1 past-paper questions, marked on your working like the exam, with a worked solution for every part.
Practise free on LemmaraMore past-paper questions on tree diagrams for dependent events
Also searched as: 4MA1 2HR June 2018 · 4MA1/2HR · 4ma1 jun18 2hr · question 16.
Lemmara is an independent study tool, not affiliated with or endorsed by Pearson Edexcel. The worked solutions are Lemmara’s own.