I agree also, its continuous, but if you also take into consideration, that any doubt of a fraction or a decimal can also be an imaginary number. The battery of the cell phone, could last as long or longer as the machine it's plugged into. You could factor the lifetime as a constant number or average number of years, plug in an X or Y which ever works for you, for a variable of numbers, and then the answer could be your imaginary number plus or minus whatever. Whatever you do should result in a continuous answer.
Posted by Jonathan Tureau

I agree that the answer is continuous, because a cell phone battery my live for 5.5 years. My College Algebra (MAC 105) professor taught our class that if the problem could possibly have a decimal (or a fraction) even if it does not, but if it just COULD, then the answer is continuous.
Posted by Sunni Krantz

Continuous. A cell phone battery could die after exactly, let's say 5 years. However, it could also die after 5 years 2 months, 4 years 9 months, etc. Since fractions are a possibility, it must be continuous.
Posted by Devon Hopkins