Skip to content

Course home

2.3 Probability

2.3 Probability

EasyMediumHard
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163
Question 132

A marine biology study classifies specimens by three characteristics: Bioluminescence (BBB), High-pressure tolerance (HHH), and Toxicity (TTT). These are represented in a Venn diagram where BBB and TTT are mutually exclusive, while HHH overlaps with both BBB and TTT. The associated probabilities for a randomly selected organism are:

  • The probability of possessing only Bioluminescence is 0.28.
  • The probability of possessing both Bioluminescence and High-pressure tolerance is 0.12.
  • The probability of possessing only High-pressure tolerance is 0.20.
  • The probability of possessing both High-pressure tolerance and Toxicity is 0.15.
  • The probability of possessing only Toxicity is 0.14.
  • The probability of possessing none of these characteristics is 0.11.

Find

a.

P(H′)P(H')P(H′)

[2]
b.

P(B∪T)P(B \cup T)P(B∪T)

[2]
c.

P(B∣H′)P(B | H')P(B∣H′)

[2]
Markscheme

2.3 Probability Questions

  1. A Level
  2. /Maths
  3. /2.3 Probability

200 exam-style questions on OCR A Level Maths 2.3 Probability, covering 2.3.1 Mutually exclusive and independent events, 2.3.2 Diagrams to assist probability calculations, 2.3.3 Conditional probability (A-level only), 2.3.4 Conditional probability from first principles (A-level only), and 2.3.5 Modelling with probability. Each one has a worked solution and a mark scheme showing where the marks go.

Question bank