There is a tree at both ends of the civic square. The distance between the two trees is 42 meters. The greening team plans to replant 20 trees at equal distances between the two trees. What is the distance between the two trees after replanting? ?
市民广场两端各有一棵树，这两棵树相距42米，绿化队计划在这两棵树之间等距离地补栽20棵树，补栽后每两棵树之间的距离是多少米？
<gadget id="calculator">2 - 1</gadget>
<output>1</output>

<gadget id="calculator">20 + 1</gadget>
<output>21</output>

<gadget id="calculator">42 / 21</gadget>
<output>2</output>

<result>2</result>