12 20/13 - 1 1/3

\(12\frac{20}{13} - 1\frac{1}{3} = 12 + 1\frac{7}{13} - 1\frac{1}{3} = 13\frac{7}{13} - 1\frac{1}{3} = 12 + \frac{21 - 13}{39} = 12\frac{8}{39}\)