Answer:
C.
![(27)/(225)=(b)/(100)](https://img.qammunity.org/2021/formulas/mathematics/high-school/7y4lhlu9sdxg87xy7upuo3b8wetuwusvmf.png)
Explanation:
To find the number of black ribbons one would have subtract the amount of red ribbons from the total number of ribbons. Then one would have to express it as a proportion. Part over whole equals percent over 100. The number of black ribbons over total ribbons equals "b" over 100.