Question 7
Alice and Bob each draw one marble without looking from a bag containing two blue marbles and one red marble. After each sees only their own marble, Alice says, “I know the colour of your marble!” If she is truthful and correct, what colour did each get? The lesson printing lists A–D; the 2017 paper also includes E.
Draw without replacement. Alice knows the initial contents and bases her certainty only on the colour she sees.
Draw without replacement. Alice knows the initial contents and bases her certainty only on the colour she sees.