Volume of one metal cube = 10&sup3; = 1,000 cm&sup3;<br>
Total volume of 5 cubes = 5 × 1,000 = 5,000 cm&sup3;<br><br>
This volume becomes the cuboid:<br>
5,000 = length × 20 × 15<br>
5,000 = length × 300<br>
Length = 5,000 ÷ 300 = \(\frac{50}{3}\) = 16.67 cm (to 2 d.p.)<br><br>
Final Answer: 16.67 cm