rope with a length of 50.24 decimeters is needed to wrap four times around the trunk of a big tree. What is the diameter of the trunk in decimeters?
绕一棵大树树干四圈需长50.24分米的绳子，树干的直径是多少分米．
<gadget id="calculator">50.24 / 4 / 3.14</gadget>
<output>4</output>

<result>4</result>