To fold a batch of paper cranes, it takes half an hour for student A to fold alone, and 45 minutes for student B to fold alone, how many minutes will it take for students A and B to fold together
折叠一批纸鹤，甲同学单独折叠需要半小时，乙同学单独折叠需要45分钟，则甲、乙两同学共同折需要多少分钟
<gadget id="calculator">1 / 30</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">1 / 45</gadget>
<output>1/45 = around 0.022222</output>

<gadget id="calculator">(1/30) + (1/45)</gadget>
<output>1/18 = around 0.055556</output>

<gadget id="calculator">1 / (1/18)</gadget>
<output>18</output>

<result>18</result>