For a pile of cement, 35% was removed in the morning and 30 tons in the afternoon, which is exactly half of it left. How many tons did this pile of cement originally have?
一堆水泥，上午运走35%，下午运走30吨，正好还剩一半．这堆水泥原来一共有多少吨？
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">35 / 100</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">1 - (1/2) - (7/20)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">30 / (3/20)</gadget>
<output>200</output>

<result>200</result>