Final answer:
Kristín will take 1.5 hours to reach the rest area while driving at a constant speed of 100 kilometers per hour.
Step-by-step explanation:
To determine how long it will take Kristín to reach the rest area that is 150 kilometers away while driving at 100 kilometers per hour, we can use the formula for time, which is time = distance ÷ speed. In this case, Kristín is driving at a speed of 100 km/h and needs to cover a distance of 150 km.
Time = 150 km ÷ 100 km/h = 1.5 hours.
So, it will take Kristín 1.5 hours to reach the rest area given that she maintains a constant speed of 100 km/h. To add context, if another car travels 150 kilometers in 3.2 hours, its average speed would be calculated as 150 km ÷ 3.2 h = 47 km/h, which is significantly lower than Kristín's speed.