An experiment consists of the following two stages: (1) first a coin is tossed (2) if the face appearing is a head, then a die is rolled; if the face appearing is a tail, then the coin is tossed again. An outcome of this experiment is a pair of the form (outcome from stage 1, outcome from stage 2). Let S be the collection of all outcomes. How many outcomes in S? A box of clothes contains 15 shirts and 10 pants. Three items are drawn from the box without replacement. What is the probability that all three are (exact fraction) all shirts or all pants? A fair coin is tossed repeatedly.
What is the probability that the second head appears at the 7th toss? (exact fraction) Suppose there's 40% chance of getting a freezing rain, 10% chance of snow and freezing rain, 80% chance of snow or freezing rain. Find the chance of snow.