Total length used $= 35\frac{5}{8} + 27\frac{1}{2} + \frac{1}{8}$

$= 35\frac{5}{8} + 27\frac{4}{8} + \frac{1}{8} = 63\frac{10}{8} = 63\frac{5}{4} = 64\frac{1}{4}$

Wait — $\frac{10}{8} = 1\frac{2}{8} = 1\frac{1}{4}$. So total $= 63 + 1\frac{1}{4} = 64\frac{1}{4}$.

But the cuts subtract $\frac{1}{8}$ inch total (material lost). So total consumed $= 35\frac{5}{8} + 27\frac{1}{2} + \frac{1}{8}$.

$35\frac{5}{8} + 27\frac{1}{2} = 35\frac{5}{8} + 27\frac{4}{8} = 62\frac{9}{8} = 63\frac{1}{8}$

$63\frac{1}{8} + \frac{1}{8} = 63\frac{2}{8} = 63\frac{1}{4}$

$\text{Leftover} = 72 - 63\frac{1}{4} = 8\frac{3}{4}$