What is the area the following circle either enter an exact answer in terms of pie or use 3.14 for pie enter your answer as a decimal. R=5 

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?