Four red and seven black beans are placed into a bag. If one of the beans is selected at random, determine the odds against the bean being red.
2 answers
The odds against red means the same as the odds for black. There are 7 black beans out of 11 so 7/11.
I will have to disagree with Jen.
The odds in favour of some event is defined as
prob(that event) : prob(not that event)
since prob(red) = 4/11
then prob(not red) = 7/11
so odds against red = (7/11) : (4/11)
= 7 : 4
The odds in favour of some event is defined as
prob(that event) : prob(not that event)
since prob(red) = 4/11
then prob(not red) = 7/11
so odds against red = (7/11) : (4/11)
= 7 : 4