Teacher Wang bought 4 chairs for 150 yuan, and the salesperson found 30 yuan. How much is each chair?
王老师用150元买4张椅子，营业员找了30元，每张椅子多少元？
<gadget id="calculator">150 - 30</gadget>
<output>120</output>

<gadget id="calculator">120 / 4</gadget>
<output>30</output>

<result>30</result>