Wang Ping and Li Jun played around a circular flower bed. They started from the same place and walked with their backs facing each other. They met after 3 minutes. Now it is known that it takes Wang Ping 5 minutes to walk around the flower bed. Ask Li Jun to walk around the flower bed. How many minutes does it take to circle.
王平和李军绕一圆形花坛游戏，他们从同一地点出发，背向而行、3分钟后两人相遇、现在已知王平绕花坛走一圈需要5分钟，问李军绕花坛走一圈要多少分钟．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/3) - (1/5)</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">1 / (2/15)</gadget>
<output>15/2 = around 7.5</output>

<result>15/2 = around 7.5</result>