# Edexcel IGCSE Maths 复习笔记 6.6.2 Combined Probability - Harder

Edexcel IGCSE Maths 复习笔记 6.6.2 Combined Probability - Harder

#### What do I need to know?

• Be aware of the basics, ie. tree diagrams, replacement, AND and OR, the sum of all probabilities is 1 (see Combined Probability – Basics)
• Note that there may be some problem-solving and algebra involved (see question 2 of the Worked Example)