Your phone service allows you to add international long distance to your phone. the cost is a $15 flat fee and then $.25 a minute for calls made. write an explicit function rule describing your monthly cost for international calls.

Aparticular telephone number is used to receive both voice calls and fax messages. suppose that 25% of the incoming calls involve fax messages, and consider a sample of 25 incoming calls. (a) what is the expected number of calls among the 25 that involve a fax message?