You are finding 3 1/6 - 1 5/6.
To solve, you should first change it so that the numerator of the first fraction is greater than the numerator of the second. Note that both have the same denominator (6). Subtract as usual:
3 1/6 = 2 7/6
2 7/6 - 1 5/6 = 1 2/6
1 2/6 is your answer.
~