A corporation was concerned about the basic educational skills of its

  

A corporation was concerned about the basic educational skills of its workers and decided to offer a selected group of them separate classes in reading and practical mathematics. 40% of these workers signed up for the reading classes and 50% signed up for the practical math classes. Of those signing up for the reading classes, 30% signed up for the practical math classes.
a. What is the probability that a randomly selected worker signed up for both classes?
b. Are the events “signs up for reading classes” and ” signs up for practical math classes” statistically independent?
c. If you were to pick 50 workers randomly with replacement, what is the probability that you would pick more than 70% who signed up for reading classes?