A point on the circumference of the circle with the equation
(x +10)2 + (y + 1)2 = 25 is

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?