Mary makes her own designed quilts at home and sells them on eBay. The following information is available for one specially designed quilt.

hours spent$/$week

$30$

current output

$15$

output under the new design

$20$

Group of answer choices

her new productivity under the new design is $0\mathrm{.}67.$

the change in her productivity under the new design is not $0\mathrm{.}15.$

her current productivity is not $0\mathrm{.}50.$

the $\%$ change in her productivity under the new design is $0\mathrm{.}67.$