Cube surface area

The cube's surface was originally 216 centimeters square. It has shrunk from 216 to 54 centimeters square. Calculate the percent change in the edge of the cube.

Correct answer:

p =  50 %

Step-by-step explanation:

$$\begin{gathered} S_1=216{\text{cm}}^2 \\ {S}_2=54{\text{cm}}^2 \\ {a}_1=\sqrt{S_1/6}=\sqrt{216/6}=6\text{cm} \\ {a}_2=\sqrt{S_2/6}=\sqrt{54/6}=3\text{cm} \\ p=(a_1-a_2)/a_1\cdot 100=(6-3)/6\cdot 100=50\% \end{gathered}$$

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