The first this you must do is pconvert it to its decimal equivalent:
62 1/2% = 62.5% = 0.625
Then, express that as a fraction and reduce it:
625 / 1000 (divide numerator and denominator by the obvious 25)
25 / 40 (divide again by 5)
5/8
Also, now you know that 5/8 = 0.625!
Hope this helps! :)