Answer:
5/12 * 300 = 125 times
explain:
I hope this answer can help
Check the picture below. Recall, is an open-top box, so, the top is not part of the surface area, of the 300 cm². Also, recall, the base is a square, thus, length = width = x.

so.. that'd be the V(x) for such box, now, where is the maximum point at?

now, let's check if it's a maximum point at 10, by doing a first-derivative test on it. Check the second picture below.
so, the volume will then be at
Answer:
The third partner owns 7/20
Step-by-step explanation:
This is true because 1/4 is 5/20 ans 2/5 is 8/20. Combined that will equal 13/20. 20-13 is 7
Therefore, the answer is 7/20.