The unit price of chairs is 20 yuan cheaper than that of desks, and the unit price of chairs is 60% of that of desks. How much is the unit price of a set of desks and chairs?
椅子比课桌的单价便宜20元，椅子的单价是课桌的60%，一套桌椅的单价是多少元？
<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">20 / (2/5)</gadget>
<output>50</output>

<gadget id="calculator">50 - 20</gadget>
<output>30</output>

<gadget id="calculator">50 + 30</gadget>
<output>80</output>

<result>80</result>