Question

If the distance between town A and town B is 5 cm on the map and 50 km in real life, then find the distance between town A and town C in real life which is 7 cm on the map. [3 Marks]

Answer 1

Solution:

The scale of the map is the ratio of the distance on the map to the corresponding distance in real life. [0.5 Mark]

The distance between two towns on the map and in real life are 5 cm and 50 km respectively.

Hence, 5 cm on the map corresponds to 50 km in real life.

5 cm : 50 km
1 cm : $\frac{50}{5}$ km. [0.5 Mark]
Therefore, the scale of the map is 1 cm : 10 km [1 Mark]
Now, distance between town A and town B is 7 cm on the map.
Hence, distance between town A and town C in real life = 7 $\times$ 10 = 70 km. [1 Mark]