How do you calculate the volume of air displaced by a balloon? Is there a formula? also, how do you calculate the mass of air displaced by balloon?

Which of the following is an example of how telecommunication devices people do their jobs? a.) a security guard checks the time using a digital watch. b.) a banker does some quick math using a solar calculator. c.) a nurse uses a digital thermometer to take a patient’s temperature. d.) a construction worker reports in to his office using a cell phone.