Question:
Tick (✓) the correct answer:
Three cubes of iron whose edges are 6 cm, 8 cm and 10 cm respectively are melted and formed into a single cube. The edge of the new cube formed is
(a) 12 cm
(b) 14 cm
(c) 16 cm
(d) 18 cm
Solution:
(a) $12 \mathrm{~cm}$
Total volume $=6^{3}+8^{3}+10^{3}=216+512+1000=1728 \mathrm{~cm}^{3}$
$\therefore$ Edge of the new cube $=\sqrt[3]{1728}=12 \mathrm{~cm}$