Answer:
312
Step-by-step explanation:
its easy
The volume of a rectangular prism is L * W * H.
We are looking for whole numbers that multiply to 28.
There are 10 possible molds.
L, W, H
-------------
28, 1, 1
1, 1, 28
14, 2, 1
1, 14, 2
1, 2, 14
7, 4, 1
4, 1, 7
7, 1, 4
7, 2, 2
2, 2, 7
-4(-4) = positive 16
Positive 16(-4) = -64
-64 is your answer