Answer:
The pair of arrows which represents the relationship of speeds of the two cars is;
The second option as shown in the attached drawing
Explanation:
The given parameters are;
The reading on the speedometer of one car = 20 m/s
The reading on the speedometer of the other car = 72 km/h = 20 m/s
The blue arrow = 20 m/s
Therefore, given that the speeds of both cars are equal (20 m/s = 72 km/h = 20 m/s), the pair of arrows that represent the relationship of speeds of the two cars is two equal length blue arrows which is the second option
The attached diagram showing the pair of arrows that represents the relationship of speeds of the two cars is drawn using Microsoft Visio.