When simplifying an exponential expression what happens to an exponent when it is moved from the numerator to the denominator or the denominator to the numerator?

Luigi is the first person to finish a 5k race and is standing 13 feet beyond the finish line. another runner, mario, is still running the race and has approximately 24 feet before he reaches the finish line. what is the distance between mario and luigi? explain through words, numbers or pictures how you found the answer.