Consider rectangular box with
- length x units (x≥0);
- width 3 units;
- height (8-x) units (8-x≥0, then x≤8).
The volume of the rectangular box can be calculated as

In your case,

Note that maximal possible value of the height can be 8 units (when x=0 - minimal possible length) and the minimal possible height can be 0 units (when x=8 - maximal possible length).
From the attached graph you can see that the greatest x-intercept is x=8, then the height will be minimal and lenght will be maximal.
Then the volume will be V=0 (minimal).
Answer: correct choices are B (the maximum possible length), C (the minimum possible height)
P/90 = 4/18
18P = 90*4 [cross-multiplication]
P = 360/18
P = 20
So, answer is P equals to 20
Answer:
38cm
Step-by-step explanation:
1. The perimeter of a square can be found with the formula
2. Since its length and width are whole numbers, it must be either
1 x 18,
2 x 9 or
3 x 6
3. Using the formula in step 1, we can found that the perimeter in these cases are
38
22
18
respectively
4. Compare those perimeter we found in previous step, it's obvious that the greatest is 38. Solved.