You did everything right. You leave "t" by itself because you don't have a given time frame. But I'll say you used the correct formula and showed your work well.
Answer:
There are 5 yellow balls
Step-by-step explanation:
40/4 = 10
10/2 = 5
y-(-2) = 1/2(x-12)
y+2 = 1/2x - 6
y = 1/2x -8
y = mx +b
The volume is 54,437.52.
