A study undertaken by the MiamiDade Supervisor of Elections

A study undertaken by the Miami-Dade Supervisor of Elections in 2002 revealed that 44% of registered voters are Democrats, 37% are Republicans, and 19% are others. If two registered voters are selected at random, find the following probability:

Exactly one voter is a Democrat.

Solution

Here we have following probabilties:

P(democrats)=0.44

P(republicans)=0.37

P(others)=0.19

Since voters are independent from each other so the probability One of them is a Democrat and another one is a Republican is

P(One of them is a Democrat and another one is a Republican)=P(democrats)P(republican)=0.44*0.37=0.1628

hence, the required probability is 0.1628.