A shopping mall wants to sell a batch of washing machines of the same model, and set the selling price at a price 20% higher than the purchase price. The estimated profit is 9,000 yuan. During the New Year’s Day, the remaining ten washing machines will be sold at a 5% higher selling price. 102% of profit. How many washing machines are there in this batch?
商场欲销售一批同一型号的洗衣机，按高于进价20%的价格定销售价，预计获利9000元，元旦期间将剩余的十台洗衣机按销售价提高5%销售，实际获利是预计获利的102%．这批洗衣机有多少台？
<gadget id="calculator">102 / 100</gadget>
<output>51/50 = around 1.02</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

<gadget id="calculator">(51/50) - 1</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">9_000 * (1/50)</gadget>
<output>180</output>

<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">180 / (1/20) / 10</gadget>
<output>360</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">360 / (6/5)</gadget>
<output>300</output>

<gadget id="calculator">360 - 300</gadget>
<output>60</output>

<gadget id="calculator">9_000 / 60</gadget>
<output>150</output>

<result>150</result>