VIDEOS ON CONDITIONAL PROBABILITY
Click on this button to go to Videos on TREE DIAGRAMS

Here is an excellent video on how to calculate conditional probabilities from Venn Diagrams


Here is an exam question on Venn Diagrams and Conditional probability. The links on the Right hand side lead to videos which go through the solutions. Try to solve the problem yourself first, then go to the videos to check your solution.
Here is another Venn Diagram and Conditional Probablity question with video solution
Here is another exam question with video Solutions