Is the distance traveled during a specific unit of time.

Speed

Explanation:

Speed is a scalar quantity, defined as the ratio between the distance covered and the time taken:

where

d is the distance covered

t is the time taken

Speed is measured in meters/second (m/s).

It should be noted that speed is different from velocity: in fact, velocity is a vector quantity, whose magnitude is defined as

where d is the displacement (not the distance), and it also has a direction, while speed does not have it.

i think it would be 80 km/h because 30 + 50 = 80 (sorry if this not the right answer i'm trying my best)