when you have to find the length of map to the actual distance, you will multiply. and if its the other way around as in finding the distance on the map, you will divide. in this case, we will be diving as it is asking the distance on the map.
a scale will always have the unit centimeter, so we will be converting 10km into centimeter.
10km = 1000000cm
1000000/125,000 = 8cm