Answer:
40 km/h
Step-by-step explanation:
You want to know the speed if 120 km were covered in 3 hours.
Speed
The relation between time, speed, and distance is ...
[tex]\text{speed}=\dfrac{\text{distance}}{\text{time}}\\\\\\\text{speed}=\dfrac{120\text{ km}}{3\text{ h}}=40\ \dfrac{\text{km}}{\text{h}}[/tex]
Her speed was 40 km per hour.
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Additional comment
The units of the answer tell you how to compute it. "Kilometers per hour" means "kilometers divided by hours."
