If you choose an answer to this question at random what is the chance you will be correct? A) 25% B) 50% C) 60% D) 25%
Follow Math Help Forum on Facebook and Google+
Spoiler: Pr[choose any letter] = 1/4 Pr[Correct]=(Pr[Correct|choose a]+Pr[Correct|choose b] + Pr[Correct | choose c] + Pr[Correct | choose d]) x 1/4 Pr[Correct] = (1/2 + 1/4 + 1/4 + 1/2) x 1/4 = 3/2 x 1/4 = 3/8 Pr[Correct] = 3/8