Answer:
C. 
Step-by-step 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.
Answer:
1/81
Step-by-step explanation:
Answer:
I don't know if this helps, just a picture not a link
64-25=39
All the square numbers are 1,4,9,16,25,36,49,64,81,100