Probability

Worked examples (14)extended set

• 1Missing probability on a spinner
• 2Solving for an unknown number of counters
• 3Relative frequency and expected numbers
• 4At least one, using the complement
• 5At least one, without replacement
• 6Expected value: is the game fair?
• 7Single events and complements
• 8Reading a relative frequency graph
• 9A spinner with unequal sectors
• 10A missing bar and a fairground game
• 11Product scores in a card-and-spinner game
• 12An unknown probability from two independent events
• 13Choosing two people from part of a Venn diagram
• 14Numbered cards and expected frequency

Worked examples (12)extended set

• 1Second stage depends on the first
• 2Working a conditional probability backwards
• 3Solving for an unknown branch probability
• 4Three draws without replacement
• 5At least two successes in three trials
• 6Forming a quadratic to find a missing number of counters
• 7Two spins with replacement
• 8Completing a tree where the second match depends on the first
• 9A tree that stops early: up to three attempts
• 10Finding the mistakes in a without-replacement tree
• 11Completing a without-replacement tree, then exactly one
• 12Two chosen from one row of a table

Worked examples (10)extended set

• 1Building a two-way table from a description
• 2Testing whether two events are independent
• 3Conditional probability from a three-set Venn diagram
• 4Two-way table with three categories
• 5Finding an unknown overlap
• 6When the two conditional probabilities disagree
• 7Completing a table with a missing entry
• 8Completing a possibility diagram for two spinners
• 9Probabilities in a Venn diagram with an unknown
• 10Conditional probability from a product grid