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Working backwards from a probability

Working backwards from a probability

Probability tree for two draws without replacement from x blue and 3 red counters, highlighting the blue then blue path and the changing fractions on the second draw

Probability equation questions ask you to work backwards from a known probability to an unknown number of counters. A tree diagram like the one above helps you keep track of what changes after the first draw.

Probability Equation Questions Lesson

  1. IGCSE
  2. /Maths
  3. /Probability Equation Questions

Step-by-step lessons covering CIE IGCSE Maths Probability Equation Questions for Core and Extended tier. Each lesson works through exam-style questions in Paper 1 and Paper 3 (Core) or Paper 2 and Paper 4 (Extended) format. Start with the Core-tier fundamentals in number and algebra before moving on to the more demanding Extended-only topics like calculus-adjacent algebra and advanced trigonometry.

Lessons