To practice interpreting verbal information, writng down
expressions for probabilities, putting the information together to
obtain an equation and solving the equation.
What are the unknowns?
What are the probabilities?
Can we obtain an equation from the information given?
If some learners can't get started suggest they have a bag and they
decide on how many red and how many blue balls are in their bag (
say 4 and 7) and then they work out the probability of drawing two
red balls and of drawing two blue balls and of drawing one ball of
each colour from their bag. Suggest that after that they use
letters for the numbers of red and blue balls (which are unknown)
and work out the probabilities in a similar way.
Fixing The Odds