It takes Xiao Zhang 36 minutes to walk from A to B, and it takes Xiao Wang 12 minutes to ride a bicycle from B to A. They set off at the same time, how many minutes before the two meet?
小张从甲地到乙地步行需要36分钟，小王骑自行车从乙地到甲地需要12分钟．他们同时出发，多少分钟后两人相遇？
<gadget id="calculator">1 / 36</gadget>
<output>1/36 = around 0.027778</output>

<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">(1/36) + (1/12)</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">1 / (1/9)</gadget>
<output>9</output>

<result>9</result>