There are 28 right handed students out of 31 total. So there are 31 - 28 = 3 left handed students. The probability of choosing a left handed student is 3/31.
28 of the 31 students are right-handed. So 31 - 28 = 3 students are left-handed. The probability of randomly choosing a lefty is [tex]\frac{3}{31}[/tex].
