SME
Grade 10 Math
Conditional probability and independence
The main lesson, then each kind of problem it solves.
Conditional probability and independence
Main lesson
A tree with conditional branches
Use this for “P(Rain) = 0.3, P(Late | Rain) = 0.4, P(Late | Dry) = 0.1. Find P(Late) and P(Rain | Late).”
Independent events: three stages
Use this for “Three trains are on time with chances 0.9, 0.8 and 0.7. What is the chance all three are? That at least one is late?”
Two draws without replacement
Use this for “A bag has 5 red and 3 blue marbles. Two are drawn without putting the first back. Find P(red, then red).”
Conditional probability on a Venn diagram
Use this for “Of 60 students, 25 drink juice, 30 milk and 10 both. What fraction of the juice drinkers drink milk?”