Suppose a-b=0a−b=0a, minus, b, equals, 0 and a, b\ne0a, b≠0a, comma, b, does not equal, 0. which one of these expressions equals \dfrac{b}{a} a b start fraction, b, divided by, a, end fraction ?

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?