Short Answer 
To solve the problem, define variables for time spent driving on the highway (h) and in the city (c), and set up the relevant equations for distance and time. By solving the system of equations, you find that the time spent in the city is 1.4 hours and on the highway is 1.6 hours.
Step 1: Define Variables
Start by setting up your variables to simplify calculations. Let h represent the time driven on the highway and c the time spent in the city. This will help in formulating the equations based on travel time and distances.
- h = Time on highway
- c = Time in city
Step 2: Set Up the Equations
Formulate equations based on the total distance traveled and the total time. You have two important equations: one for the distance and one for the total time. The distance equation combines distances traveled at different speeds, while the time equation is the total travel duration.
- Distance: 45h + 20c = 100
- Time: h + c = 3
Step 3: Solve the System of Equations
Next, solve the equations to find the values of h and c. Start by isolating h in the time equation and substituting it into the distance equation. This will allow you to find the value of c, which represents the city driving time.
- Substituting gives you: c = 1.4 hours
- Use h + 1.4 = 3 to find h = 1.6 hours