The given scale for the map means that a distance of 1 cm between two locations on the map corresponds to a real distance between them of 600,000 cm = 6 km.
So, if the distance between two places in reality is 87 km, on the map this would be represented by a distance of 14.5 cm, since
87 = 84 + 3
87 = 6 • 14 + 6 • (1/2)
87 = 6 • (14 + 1/2)