Scale Drawing: What is the real length of the bus

[dave3]

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 workout: 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.

 

[skeeter]

Re: Scale Drwaing

$\dfrac{3 \, m}{4 \, cm} = \dfrac{x}{10 \, cm}$

$x = \dfrac{(3 \, m)(10 \, \cancel{cm})}{4 \, \cancel{cm}} = 7.5 \, m$