A town planner measures 2000mm on a map of scale 1:500 and for the same distance on a map of unknown scale, she measures 500mm. What is the scale of the second map?

If the scale on the first map is increased by 20% what is the new scale

1 answer

To find the scale of the second map, we can set up a proportion with the distance measured on both maps.

On the first map, the distance is 2000mm with a scale of 1:500.
On the second map, the distance is 500mm with an unknown scale.

Let x represent the scale of the second map.

The proportion can be set up as:

2000mm/500mm = 1:500/x

Cross multiplying gives:

2000x = 500 * 500

Simplifying gives:

2000x = 250000

Dividing both sides by 2000 gives:

x = 250000 / 2000

x = 125

So, the scale of the second map is 1:125.

To find the new scale if the scale on the first map is increased by 20%, we can simply multiply the original scale by 1.2.

Original scale: 1:500

New scale: 1.2 * 1:500

New scale: 1:600

The new scale is 1:600.