Answer and explanation:
Discrete random variables can be counted as integers and you can't divide them. Continuous random variables are counted as real numbers and are magnitudes that can´t be counted as an exact number (there will always be an uncertainty in the measurement).
a. The random variable is continuous. Distance is a measurement.
b. The random variable is discrete. You can count how many people are sitting at a computer.
c. The random variable is continuous. Weight is a measurement.
d. The random variable is discrete. You can count how many fishes were caught.
e. The random variable is discrete. You can count how many hints a web site had.