The first piece was
[tex]16in[/tex]The second piece was twice as long. Therefore, the second piece was
[tex]2\times16in=32in[/tex]The total amount of ribbon she used was:
[tex]16in+32in=48in[/tex]Now, let's convert that into ft using a rule of three:
Therefore,
[tex]x=\frac{48}{12}\rightarrow x=4ft[/tex]She needed to cut a total of 4ft of ribbon
(Answer D)