Question

The scale of a map is given as 1: 30000. Two cities are 4 cm apart on the map. Find the actual distance between them.

Answer 1

Let the actual distance be x cm. Since the distance on the map is directly proportional to the actual distance,
1: 30000 = 4: x
Since the product of the means is equal to the product of the extremes.
$x\times 1=30000\times 4$
x = 120000
Hence, the actual distance between them is 120000 cm or 1.2 km.