If three cubes with a surface area of 15 square centimeters are put together to form a cuboid, the surface area will be reduced by how many square centimeters.
把3个表面积是15平方厘米的正方体，拼成一个长方体，表面积比原来减少多少平方厘米．
<gadget id="calculator">15 / 6</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">(5/2) * 4</gadget>
<output>10</output>

<result>10</result>