Maya and mabel are inspecting a 80: 1 scale floor plan of their new house. the dimensions of the living room in the scaled plan are 4cm by 5cm. what is the area of the living room in the real world?

An 80:1 scale means that for every unit on a diagram, there are 80 units in the real world.  So, this means that the floor plan is (80x4) x (80x5) cm, which equals 320 x 400 cm. 
If you want to further simplify your answer, this translates to 3.2 meters x 4 meters

Is it multiple choice

Ithink you’re answering is d