Mathematics for IGCSE & O level - Similarity (Section 2 - No. 30)

If a model drawn an area of 5m² in real life is represented by 20 cm² on the model, what is the scale?

1:5

1:25

1:50

1:100

5 m² is equivalent to 50,000 cm². Scale factor is the square root of (50000/20) = 50, hence the scale is 1:50.