The school bought 30 sets of tables and chairs. The unit price of the tables is twice that of the chairs, and the unit price of the chairs is 40 yuan. How much more is the table than the chairs?
学校买来30套桌椅，桌子的单价是椅子的2倍，椅子单价是40元，买来桌子比椅子多多少元？
<gadget id="calculator">40 * 2</gadget>
<output>80</output>

<gadget id="calculator">80 - 40</gadget>
<output>40</output>

<gadget id="calculator">40 * 30</gadget>
<output>1_200</output>

<result>1_200</result>