Errors in a billing process often lead to customer dissatisfaction and ultimately hurt bottom-line profits. An article

Question:

Errors in a billing process often lead to customer dissatisfaction and ultimately hurt bottom-line profits. An article in Quality Progress (L. Tatikonda, "A Less Costly Billing Process," Quality Progress, January 2008, pp. 30-38) discussed a company where 40% of the bills prepared contained errors. If 10 bills are processed, what is the probability that
a. 0 bills will contain errors?
b. Exactly 1 bill will contain an error?
c. 2 or more bills will contain errors?
d. What are the mean and the standard deviation of the probability distribution?