Ray should buy the first one because it has the greater volume by 1,440 square inches.
Tank 1: 20x20x18=7,200
Tank 2: 40x12x12=5,760
7,200-5,760=1,440
36÷4. 4 goes into 36, 9 times. Do your check work, which would be 9x4=36√. Hope that helps!
Answer: 17
It’s 17 because they are the same shape and size just are flipped