A certain toy store bought 10 remote-controlled airplanes with a unit price of 200 yuan, sold 7 planes at a profit of 50 yuan each, sold 2 planes at a profit of 35 yuan each, and sold the remaining 1 plane at the purchase price. What is the profit margin for the toy store selling these remote-controlled airplanes? (Profit rate=((profit)/(purchase price))*100%)
某玩具店购进了10架单价为200元的遥控飞机，按每架50元的利润卖了7架，按每架35元的利润卖了2架，剩下的1架按进价销售．该玩具店销售这批遥控飞机的利润率是多少？(利润率=((利润)/(进价))*100%)
<gadget id="calculator">50 * 7</gadget>
<output>350</output>

<gadget id="calculator">35 * 2</gadget>
<output>70</output>

<gadget id="calculator">350 + 70</gadget>
<output>420</output>

<gadget id="calculator">200 * 10</gadget>
<output>2_000</output>

<gadget id="calculator">420 / 2_000</gadget>
<output>21/100 = around 0.21</output>

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

<gadget id="calculator">(21/100) * 1</gadget>
<output>21/100 = around 0.21</output>

<result>21/100 = around 0.21</result>