Lemmara logoLemmaraWorked solution

4MA1/2F Jun 2018, Question 14: Combined Events with Two-Way Tables

Pearson Edexcel International GCSE Mathematics A 4MA1 · Paper 2F (Foundation) · Calculator · 4 marks

اقرأ هذا الحل مشروحاً بالعربي ←

The question, in short

Two sets of four cards A, B, C, D; one card drawn at random from each set, with a table of all 16 pairs. Find a probability and an expected count over 80 repeats.

Summarised in our own words. Use the official paper for the exact wording and any diagrams.

Part (a) · 2 marks

Using the 16 equally likely pairs, find the probability that at least one of the two cards drawn is marked C.

  1. 1List all outcomes with at least one C: AC, BC, CC, DC, CA, CB, CD
  2. 2Count the successful outcomes: 7
  3. 3Total possible outcomes: 16
  4. 4Probability = 7/16

Answer7/16

Part (b) · 2 marks

Cards are replaced each time; over 80 independent repeats, estimate how many times at least one card marked C is taken.

  1. 17 of the 16 pairs have at least one C, so P = 7/16.
  2. 2Estimate = 7/16 × 80
  3. 380 ÷ 16 = 5, and 7 × 5 = 35

Answer35

Stuck on a step? Read the free lesson: Combined Events with Two-Way Tables

Practise more combined events with two-way tables questions

Real 4MA1 past-paper questions, marked on your working like the exam, with a worked solution for every part.

Practise free on Lemmara

More past-paper questions on combined events with two-way tables

Also searched as: 4MA1 2F June 2018 · 4MA1/2F · 4ma1 jun18 2f · question 14.
Lemmara is an independent study tool, not affiliated with or endorsed by Pearson Edexcel. The worked solutions are Lemmara’s own.