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.
There is no answer as this isn't an equation. And moreover it's in its simplest form.
Answer:
0.08 minutes for a kilometer.
Step-by-step explanation:
If the track is 25 kilometers, and he runs 25 kilometers in 2 minutes, he runs a kilometer in 2÷25 minutes or 0.08 minutes which is 4.8 seconds.
I'm pretty sure the track isn't 25 kilometer or he can't run a lap in 2 minutes. But if so, the answer is 0.08 minutes.
-6n-20=-2n+4-12n
-6n-20=-14n+4
+6n +6n
-20=-8n+4
-4 -4
-24=-8n
/8 /8
n=-3
-