There are 27 classes in Guangming Primary School. Each class will spend a total of 189 yuan to buy a washbasin and a towel. Each towel is 3 yuan. How much is each washbasin?
光明小学共27个班，每班各买一个脸盆和一条毛巾一共要用去189元，每条毛巾3元，每个脸盆多少元？
<gadget id="calculator">189 / 27</gadget>
<output>7</output>

<gadget id="calculator">7 - 3</gadget>
<output>4</output>

<result>4</result>