A mile is a unit of length, usually used to measure distance, in a number of different systems. In contemporary English contexts, mile most commonly refers to the statute mile of 5,280 feet (exactly 1,609.344 meters) or the nautical mile of 1,852 meters (about 6,076.1 ft). (src: http://en.wikipedia.org/wiki/Mile)
An international or statute mile is 1,609.344 meters.
5 / 1.609 = 3.1 and 5 / 1.852 = 2.7
So: 3.1 international miles go in 5 kilometers.
2.7 nautical miles go in 5 kilometers.