Quick question!?

Which of the following is not an example of a discrete random variable?





a) the number of heads observed for ten coin tosses


b) the mass of an apple randomly chosen from a supermarket bin


c) the sum resulting from the roll of two six-sided dice


d) number of hearts in a randomly chosen hand of seven playing cards

Quick question!?
Discrete Random Variables


A probability distribution is a table of values showing the probabilities of various outcomes of an experiment.





For example, if a coin is tossed three times, the number of heads obtained can be 0, 1, 2 or 3. A discrete variable is a variable which can only take a countable number of values. In this example, the number of heads can only take 4 values (0, 1, 2, 3) and so the variable is discrete. The variable is said to be random if the sum of the probabilities is one.
Reply:probably c, since you have more ways to get 7 than any other number. But I'm not sure that's what discrete random variable means.
Reply:b) because it can be given to unlimited accuracy, e.g. 212.3242334524etc grams.





edit


DanE's answer is better though!
Reply:B.


Mass is continuous, not discreet.
Reply:b) There is no discrete unit of mass (though, the quantum physicists might disagree).