Ewen has 48 white tiles and 16 blue tiles.
We need to find the ratio of the number of white tiles to the number of blue tiles in the simplest form, that is

And to write it in simplest form, we need to find the greatest common factor of 48 and 16, and divide both of them by that factor .
And the greatest common factor of them is 16, and on dividing by 16, we will get

So the required answer is
