A pile of coal is burned in three days, 120 kg is burned on the first day, and 1/2 of the total amount is burned on the second day. At this time, the ratio of the burned coal to the remaining coal is 5:2. How much is this pile of coal? kilogram?
一堆煤三天烧完，第一天烧了120千克，第二天烧了总数的(1/2)，这时烧去的煤与剩下的比是5：2，这堆煤有多少千克？
<gadget id="calculator">5 + 2</gadget>
<output>7</output>

<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(5/7) - (1/2)</gadget>
<output>3/14 = around 0.214286</output>

<gadget id="calculator">120 / (3/14)</gadget>
<output>560</output>

<result>560</result>