The volume of water stays the same when transferred.<br><br>
&bull; Water volume = 30 × 24 × 6 = 4320 cm&sup3;<br>
&bull; In the new tank: \(\frac{1}{4}\) full at height 12 cm<br>
&bull; \(\frac{1}{4}\) × base area × 12 = 4320<br>
&bull; 3 × base area = 4320<br>
&bull; Base area = 4320 ÷ 3 = 1440 cm&sup2;<br><br>
Final Answer: 1440 cm&sup2;