On a map of what scale is the distance from Moscow to Murmansk 1500 km depicted as a 6 cm line?

The standard by which the scale designation is made on geographical maps is described as follows:

on the left side – the unit is indicated, as an indicator that one centimeter on the map contains a certain amount of distance on the real map;

on the right side after the colon – the number of centimeters in reality.

Taking into account the fact that 1500 km by 6 cm fit, then in one centimeter there will be 250 kilometers.

And this: 250,000,000 centimeters.

Thus, the scale will be indicated in the form:

1:25 000 000