Answer:
a) Simple random sample
b) Random sample
c) None of them.
Step-by-step explanation:
a) This would be a simple random sample given that the dice roll is a random method to select the students and the probability of each outcome of the dice is 1/6.
b) This would be a random sample, given that the cards are shuffled, this is a random event. However, there's a condition on how to select the cards (The top ones are chosen) and therefore this can not be a simple random sample since not all cards have the same probability of being selected.
c) This is not a random sample since there is an specific condition on how to choose the students (by their age)