The chorus team bought 30 tops for 4500 yuan and 30 pairs of trousers for 3600 yuan. How much is a pair of pants cheaper than a top? (answered in two different ways)
合唱队买了30件上衣用去4500元，买30条裤子用去3600元．一条裤子比一件上衣便宜多少钱？(用两种不同方法解答)
<gadget id="calculator">4_500 / 30</gadget>
<output>150</output>

<gadget id="calculator">3_600 / 30</gadget>
<output>120</output>

<gadget id="calculator">150 - 120</gadget>
<output>30</output>

<gadget id="calculator">900 / 30</gadget>
<output>30</output>

<result>30</result>