IXL Grade 8 H.13 Scale Drawings and Scale Factor Examples

Four examples of how to find scale factor and how to use the scale of a drawing to find distances.

[pawallimbu]

QS) A model of a bus has a scale of 4cm to 3m. The model is 10cm long. What is the real length of the bus?

my working: 4cm to 3m. 4 cm is length of model and 3m is real length.
so we have, mode = 10 cm long

so 4 cm to 10 cm: 10/4= 2.5 cm

for real length 3 X 2.5= 7.5 m.

I am not sure about my ans. Do i need to convert cm to m? Please anyone give better explanation. Thank you.