cylindrical iron rod with a base area of 30 square centimeters and a length of 50 cm is cast into a conical iron rod with a length of 45 cm. What is the base area of this iron rod?
一根圆柱形铁棒，底面积是30平方厘米，长是50厘米，把它铸造成一个长45厘米的圆锥形铁棒，这个铁棒的底面积是多少？
<gadget id="calculator">3 / 45</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">30 * 50 * (1/15)</gadget>
<output>100</output>

<result>100</result>