Answer: 30 inches
Explanation:
We know that the formula for calculate the volume of a cube is:
![V=s^3](https://img.qammunity.org/2020/formulas/mathematics/middle-school/v7hoqafhpvetd00xe2yni94jab8i2xi0ei.png)
Where "s" is the length of each side.
Since the volume of each cube-shaped box is 125 cubic inches, we can find "s":
![125\ in^3=s^3\\\\\sqrt[3]{125\ in^3}=s\\\\s=5\ in](https://img.qammunity.org/2020/formulas/mathematics/middle-school/b8jy96quni8wdp91pdufqt15o5g9mqyi4t.png)
We know that the display has six layers of boxes, then , to calculate the height of the display, we can multiply the value of "s" obtained before by 6. Then:
![height=(5\ in)(6)=30\ in](https://img.qammunity.org/2020/formulas/mathematics/middle-school/bc0j8i8v3com0c1aimyy3509dpqvv5vinj.png)