if the ratio between an english pound and a euro is 3 to 4 respectivley, the ratios will hold true for any number. Since 33/3 = 11, we can stratigically multiply by 1,
3/4 = (3/4)(11/11)
so the ratios would be the same, multiplying, you would get 33/44, which means 33 pounds for 44 euros