in a model of ship the mast is 9m high while. if the length of the actual ship is12m high.if the lenght of the ship is 28m. how long is model of ship?

Given,

lenght of model ship=9m
lenght of real ship=12m
that means,there is 3m difference between the lenght of real ship and model ship.
therefore,
if the length of the ship is 28m
then the lenght of the model ship=28-3=25m
so,the lenght of the model ship=25m.