Xingwang Company has a pile of coal, totaling 280 tons. On the first day (2/7) more than 1 ton was used, on the second day (3/8) less than 12 tons of the total amount was used, on the third day (3/10) more than 10 tons of the total amount was used , how many tons are left?
兴旺公司有一堆煤，共280吨．第一天用去了(2/7)多1吨，第二天用去了总量的(3/8)少12吨，第三天用去了总量的(3/10)多10吨，还剩多少吨？
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">280 * (2/7)</gadget>
<output>80</output>

<gadget id="calculator">80 + 1</gadget>
<output>81</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">280 * (3/8)</gadget>
<output>105</output>

<gadget id="calculator">105 - 12</gadget>
<output>93</output>

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

<gadget id="calculator">280 * (3/10)</gadget>
<output>84</output>

<gadget id="calculator">84 + 10</gadget>
<output>94</output>

<gadget id="calculator">280 - 81 - 93 - 94</gadget>
<output>12</output>

<result>12</result>