Find total volume, divide by 9, then divide by the small base area.<br><br>
&bull; Total water = 30 × 14 × 12 = 5040 cm&sup3;<br>
&bull; Each small cuboid = 5040 ÷ 9 = 560 cm&sup3;<br>
&bull; Base of each = 10 × 8 = 80 cm&sup2;<br>
&bull; Height = 560 ÷ 80 = 7 cm<br><br>
Final Answer: 7 cm