There are two pencils one is 14 cm long the other is x cm long if x equals to 10 what is the total length of the two pencils solving

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?