SOLUTION: If the odds against Ealgenton winning the election are 2 to 7, then what is the probability the eagleton will win the election?

These are all equivalent:

odds against = f:s, odds in favor = s:f,  probability =  

Substituting f=2, and s=7 

odds against = 2:7, odds in favor = 7:2, probability =  = 

Edwin