Answer:
well, there are three possible answers. 24 square cm, 18 square cm, and 12 sqaure cm.
Step-by-step explanation:
L*W is base, and base times H, Height, gives you the volume of a three dimensional shape. The base depends on what the height is, so if there was a diagram i would be able to help you more. Its either 6*4 with 3 height, 6*3 with 4 height, or 3*4 with 6 height.
Since the question is so vague, I am not sure if thats what you are asking, so heres another answer: you want the combined total of the rectangle if you were to flatten it out. If so, then you have two 24 square cm sides, two 18 square cm sides, and two 12 cm sides. Add this up and you get the total area.
12*2+18*2+24*2 = 108
Juice is 20-cup * 75% = 15-cup, now water and juice are in total (4+20)-cup, so the percent of juice should be 15/24=62.5%
