IGCSE Maths / Probability

Conditional probability without replacement

Edexcel International GCSE Maths (4MA1), chapter 20: Probability, specification point 6.3c. Part of the full course.

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Without replacement, the probability of a second event depends on what happened first. Use the tree branches to find conditional probabilities, then multiply along a path when the question asks for both events.

More lessons in Probability

• The language of probability and the probability scale
• Listing outcomes systematically
• Theoretical probability and sample space
• Relative frequency and mutually exclusive events
• Expected frequency and relative frequency
• Multiplying independent probabilities
• At least one, and the complement
• Tree diagrams with replacement
• Tree diagrams without replacement
• Three stage tree diagrams
• Probability problem solving
• Conditional probability from a two way table
• Conditional probability from a Venn diagram
• Forming an equation from a probability