Atree is 6 feet tall now. it is expected to grow 2 feet a year. in how many years id the tree expected to be 30 feet tall?

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?