A trapezoidal sesame field has an upper base of 280 meters, a lower base of 120 meters, and a height of 50 meters. On average, 10 tons of sesame seeds can be harvested per hectare. How many tons of sesame can be harvested in this land?
一块梯形的芝麻地，上底是280米，下底是120米，高是50米，平均每公顷收芝麻10吨．这块地一共可收芝麻多少吨？
<gadget id="calculator">280 + 120</gadget>
<output>400</output>

<gadget id="calculator">50 / 2 / 10_000</gadget>
<output>1/400 = around 0.0025</output>

<gadget id="calculator">400 * (1/400) * 10</gadget>
<output>10</output>

<result>10</result>