"percent" (%) means taking a hundredth, so x% = x/100. 54% = 54/100 = 27/50. Since 27 = 3x3x3 and 50 = 2x5x5, the fraction 27/50 is irreducible and in its simplest form.

The word "percent" means per one hundred. So simply write the percentage value as a fraction over 100 and then simplify if required. For example: 75% = 75/100 which simplifies to 3/4 (by dividing top and bottom by 25). 54% = 54/100 which simplifies to 27/50 (by dividing top and bottom by 2).

If by "54" you mean ".54", then that decimal converted to a fraction is 54/100, which can be simplified to 27/50. If by "54" you mean ".54545454... etc" (repeating), that decimal converted to a fraction is 6/11. (WikiAnswers really needs to allow periods in their questions, it's not your fault.)