Question

In a model of a ship, the mast is 9 cm high, while the mast of the actual ship is 12 m high. If the length of the ship is 28 m, how long is the model ship?

Answer 1

Let the length of the mast of the model ship be x cm.
The given information in the form of a table is as follows:

-	Height of mast	Length of ship
Model ship	9 cm	x
Actual ship	12 m	28 m

We know that the dimensions of the actual ship and the model ship are directly proportional to each other. 
Therefore, we obtain:
\(\frac{12}{9}=\frac{28}{x}\)
\(⇒ x=\frac{28×9}{12}=21 cm\)
Hence, the length of the model ship is 21 cm.