You travel 2,557 km in 190 days how far did you travel per hour

What it is asking for is a distance over time in HOURS. 
It isn't specific about the distance units so, we can assume km is OKAY to use!

Now we need to convert 190 days to hours. Let's set up some conversion factors. 

1 Day = 24 Hours



I recommend setting up conversions like the way I did above. To do so simply make the units cancel out. Similar to how 3/3 cancel out, units also cancel out in the same way. So when you are trying to figure out whether or not you divide or multiply by the conversion factor simply use this method. Say we had 190 hours, the hours unit would need to be on the bottom, and the days on top. It'd be 1/24, thus you would divide by 24. 

= 4560 hours.

Now what it is asking for his a rate of distance per hour. This rate is also called speed. Remember in the statement it said how far per hour. Meaning when dividing the units should look like this: 

= 0.5607

The answer is: 
0.5607