A self-employed person buys 500 kilograms of live fish and spends 200 yuan for shipping. When the fish is sold, the dead fish account for 10% of the total. The price per kilogram of fish?
某个体户买进500千克活鱼，用去运费200元，到出售时死去的鱼占总数的10%，剩下的活鱼以每千克6.5元出售，仍可得30%利润，求买进时每千克鱼的价格？
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 - (1/10)</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 + (3/10)</gadget>
<output>13/10 = around 1.3</output>

<gadget id="calculator">6.5 / (13/10)</gadget>
<output>5</output>

<gadget id="calculator">500 * (9/10) * 5</gadget>
<output>2_250</output>

<gadget id="calculator">2_250 - 200</gadget>
<output>2_050</output>

<gadget id="calculator">2_050 / 500</gadget>
<output>41/10 = around 4.1</output>

<result>41/10 = around 4.1</result>