Answer :
5/6 x 4/5= 20/30 ----->2/3 Used for dress
5/6 -2/3= amount used for jewel box ---> 1/6 yard
5/6 -2/3= amount used for jewel box ---> 1/6 yard
[tex]amount\ used\ for\ jewel\ box=all\ lace-\ lace\ used\ for\ dress\\\\\
amount\ used\ for\ jewel\ box=\frac{5}{6}-\frac{4}{5}=\frac{25}{30}-\frac{24}{30}=\frac{1}{30}\\\\ \frac{1}{30}\ of\ lace\ is\ for\ jewel\ box.
[/tex]