Thanks to a Generous and Eccentric Donor, the School of Business

Multiple Choice

Thanks to a generous and eccentric donor, the school of business has 3 fax machines.The toner in each machine needs to be changed after about 5 hours of use.There is one unit secretary who is responsible for the fax machine maintenance.It takes him 15 minutes to replace the toner cartridge.What is the probability that none of the fax machines need toner?

A) 1.1500
B) 1.1658
C) .8578
D) .7696