The school bought back a batch of skipping ropes. There were 18 long ropes and three times as many short ropes as the long ropes. How many skipping ropes did the school buy in total?
学校买回一批跳绳，长绳有18根，短绳是长绳的3倍．学校一共买回多少根跳绳？
<gadget id="calculator">18 * 3</gadget>
<output>54</output>

<gadget id="calculator">54 + 18</gadget>
<output>72</output>

<result>72</result>