In a cylindrical water tank with a base radius of 30 cm, a cone with a height of 24 cm is submerged. When the cone is pulled out of the water, the water level drops by 2 cm. What is the radius of the base of the cone?
在一个底面半径是30厘米的圆柱形储水桶里，浸没着一个高为24厘米的圆锥体，把它从水里捞出时，水面下降2厘米，这个圆锥的底面半径是多少？
<result>15</result>