A drawing of a building with a scale of 1:100 shows that its length is 80cm, and the known ratio of length to width is 4:1. What is the actual floor area of the building

A drawing of a building with a scale of 1:100 shows that its length is 80cm, and the known ratio of length to width is 4:1. What is the actual floor area of the building

80x100=8000(cm)=80(m)
80/4=20(m)
80x20 = 1600 (M2)