Hamilton left home at 2:00 pm and entered the desert at 4:30 pm, so he drove in the city for:

1. The clock times give the elapsed time. 2. 2:00 pm to 4:30 pm is two and a half hours of driving. 3. Two hours are counted on the congested freeways. _Source: OpenStax Elementary Algebra 2e, Chapter 3, Uniform Motion Applications (CC BY 4.0)._