The store sells 120 yellow balloons, and sells 42 red balloons 3 times less than the yellow balloons, how many red balloons are sold?
商店卖出120个黄气球，卖出的红气球比黄气球的3倍少42个，卖出多少个红气球？
<gadget id="calculator">120 * 3</gadget>
<output>360</output>

<gadget id="calculator">360 - 42</gadget>
<output>318</output>

<result>318</result>