In order to solve this problem, let's use a rule of three:
20 robots need 1 1/4 yards of wire,
16 robots need x yards of wire:
[tex]\begin{gathered} \frac{20}{16}=\frac{1\frac{1}{4}}{x} \\ \frac{20}{16}=\frac{\frac{5}{4}}{x} \\ 20x=16\cdot\frac{5}{4} \\ 20x=4\cdot5 \\ 20x=20 \\ x=\frac{20}{20}=1 \end{gathered}[/tex]So we need 1 yard of wire to make 16 robots.