Twenty-Five Percent of the Employees of a Large Company Are

Twenty-five percent of the employees of a large company are minorities. A random sample of 7 employees is selected.
a. Define the random variable in words for this experiment.
b. What is the probability that the sample contains exactly 4 minorities?
c. What is the probability that the sample contains fewer than 2 minorities?
d. What is the probability that the sample contains exactly 1 non-minority?
e. What is the expected number of minorities in the sample?
f. What is the variance of the minorities?