The school bought a set of desks and chairs. The chairs are 80 yuan cheaper than the desks. The unit price of the chairs is 60% of the desks. How much does the school have to pay for this set of desks and chairs?
学校买来一套课桌椅，椅子比课桌便宜80元，椅子的单价是课桌的60%，学校买这套课桌椅一共要付多少元？
<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">80 / (2/5)</gadget>
<output>200</output>

<gadget id="calculator">200 - 80</gadget>
<output>120</output>

<gadget id="calculator">120 + 200</gadget>
<output>320</output>

<result>320</result>