The garment factory used 84m cloth to make 18 sets of adult clothes and 15 sets of children's clothes. Each set of adult clothes used 3m of cloth. How many meters of cloth was used for each set of children's clothes?
服装厂用84m布刚好做成了18套成人服装和15套儿童服装，每套成人服装用布3m，每套儿童服装用布多少米？
<gadget id="calculator">3 * 18</gadget>
<output>54</output>

<gadget id="calculator">84 - 54</gadget>
<output>30</output>

<gadget id="calculator">30 / 15</gadget>
<output>2</output>

<result>2</result>