The Records of a Department Store Show That 20% of Its

Short Answer

The records of a department store show that 20% of its customers who make a purchase return the merchandise in order to exchange it. In the next six purchases,
a.what is the probability that three customers will return the merchandise for exchange?
b.what is the probability that four customers will return the merchandise for exchange?
c.what is the probability that none of the customers will return the merchandise for exchange?