Trees are planted on one side of a 30-meter-long section of the road. A total of 4 trees are planted from the beginning to the end (both ends are planted). What is the distance between two adjacent trees in meters?
在30米长的一段路的一侧植树，从头到尾(两端都栽)共植了4棵树，相邻两棵树之间的距离是多少米．
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">30 / 3</gadget>
<output>10</output>

<result>10</result>