Given the following sets. A = {0, 1, 2, 3} B = {a, b, c, d} C = {0, a, 2, b} Find A C. {0, 2} {a, b, c, d} {0, 1, 2, 3} empty set {0, a, 2, b}

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?