The fourth grade students are going to buy costumes for theatrical performances. If they buy 30 sets, there will be 120 yuan left. If they buy 35 sets, there will be 20 yuan left. How much is each suit?
四年级同学准备去买文艺演出的服装，如果买30套，还剩120元，如果买35套，还剩20元，问每套衣服多少元？
<gadget id="calculator">120 - 20</gadget>
<output>100</output>

<gadget id="calculator">35 - 30</gadget>
<output>5</output>

<gadget id="calculator">100 / 5</gadget>
<output>20</output>

<result>20</result>