Mathematics

Problem

A metal cube expands as it is heated. When the edge length is

3\,\text{cm}

, the volume is increasing at

225\,\text{cm}^{3}/\text{min}

. At that instant, how fast is the cube’s surface area increasing? a)

450\,\text{cm}^{2}/\text{min}

300\,\text{cm}^{2}/\text{min}

900\,\text{cm}^{2}/\text{min}

75\,\text{cm}^{2}/\text{min}