The school buys 10 sets of desks and chairs for 500 yuan. It is known that the unit price of the desk is four times the unit price of the stool. How much is each desk?
学校买10套课桌椅用500元，已知桌子的单价是凳子单价的4倍，每张桌子多少元？
<gadget id="calculator">500 / 10</gadget>
<output>50</output>

<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<gadget id="calculator">50 / 5</gadget>
<output>10</output>

<gadget id="calculator">10 * 4</gadget>
<output>40</output>

<result>40</result>