# Math Help - Scale distance

1. ## Scale distance

a map is drawn to a scale 1: 2 500 000. what is distance in kilometres between town A and town B 16.3cm apart? I get confused when trying to find metres and kilometres.

2. Originally Posted by mat
a map is drawn to a scale 1: 2 500 000. what is distance in kilometres between town A and town B 16.3cm apart? I get confused when trying to find metres and kilometres.
Let $d_m$ denote the distance on the map and $D_{AB}$ the actual distance between the places A and B.

Then you know:

$\dfrac{d_m}{D_{AB}}= \dfrac{1}{2,500,000}$

You'll get:

$D_{AB} = d_m \cdot 2,500,000$ Sub in the value of $d_m$ and you'll get

$D_{AB}= 40,750,000\ cm$

1. Divide by 100 to get meters
2. Divide by 1000 to get km

3. $D_{AB}=407.5\ km$