6.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?

Given: We have 9cm as the lenght of the model for which 12 cm is the actual length.So, for 28 cm of actual length ,let x be the length of the model

We can see this is the case of direct proportion,So we have

\(\frac{9}{12}=\frac{x}{28}\)

\(\Rightarrow x=28\times \frac{9}{12}\)

\(\Rightarrow x=21 cm\)

Hence, the length of the model ship is 21 cm.