batch of fruits shipped from the south, sold in two categories, the big ones are 5.4 yuan per kilogram, and the small ones are 4.2 yuan per kilogram. In this way, the total price is 3540 yuan. If the price is reduced by 0.2 yuan per kilogram, this batch of fruits can be sold for 3400 yuan. Ask How much is the big fruit?
南方运来一批水果，分两类卖，大的每千克5.4元，小的每千克4.2元，这样共卖得3540元，如果每千克降价0.2元，这批水果就能卖3400元，问其中大水果多少元？
<gadget id="calculator">3_540 - 3_400</gadget>
<output>140</output>

<gadget id="calculator">140 / 0.2</gadget>
<output>700</output>

<gadget id="calculator">4.2 * 700</gadget>
<output>2_940</output>

<gadget id="calculator">3_540 - 2_940</gadget>
<output>600</output>

<gadget id="calculator">5.4 - 4.2</gadget>
<output>1.2</output>

<gadget id="calculator">600 / 1.2</gadget>
<output>500</output>

<gadget id="calculator">5.4 * 500</gadget>
<output>2_700</output>

<result>2_700</result>