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IB Maths AI SL 4.5 Probability Basics

IB Maths AI SL 4.5 Probability Basics
IB Mathematics: applications and interpretation guide, first assessment 2021

Practise defining events and sample spaces and calculating probabilities from counts, tables, diagrams or relative frequency, including complements and expected occurrences.

How this is tested

  • list or count the relevant outcomes before dividing favourable outcomes by the sample-space total
  • read the correct cell, sector or Venn region and express its probability in a suitable form
  • identify a complement as every outcome outside the named event and use P(A') = 1 - P(A)

Question 3(a)(i)

Hawksburn Aviation School offers three courses, flying, management and engineering. The following information was collected about the 50 students enrolled in courses at the school.
- 21 students are enrolled in the flying course only.
- 14 students are enrolled in both the flying course and the management course.
- Students enrolled in the engineering course are not enrolled in any other courses.
The information about all 50 students is presented in the following Venn diagram.

Figure for Question 3(a)(i) — IB Maths AI SL

A student is selected randomly from this group.

Find the probability that

the student is enrolled in the flying course;