Answer:
Charlotte has run 5 km for the first 20 minutes of the race. 
Explanation:
This is deduced from her training speed of 1 km every 4 minutes.
If we multiply the 20 minutes by the speed at which he has run (
 =
 = 
 ):
):
 * 20 minutes = 5 km
 * 20 minutes = 5 km 
We obtain the distance he has traveled in 20 minutes at a constant speed of 
 .
.
Have a nice day!