There are two piles of coal, A and B, with a total of 90 tons. If 5 tons are taken from pile A and put into pile B, the coal in pile A happens to be pile B (7/11). How many tons of coal is there in Pile A?
有甲、乙两堆煤共90吨．如果从甲堆取5吨放入乙堆，这时甲堆的煤正好是乙堆的(7/11)．原来甲堆煤有多少吨？
<gadget id="calculator">7 / 11</gadget>
<output>7/11 = around 0.636364</output>

<gadget id="calculator">(7/11) * 90</gadget>
<output>630/11 = around 57.272727</output>

<gadget id="calculator">(7/11) * 5</gadget>
<output>35/11 = around 3.181818</output>

<gadget id="calculator">5 + (630/11) + (35/11)</gadget>
<output>720/11 = around 65.454545</output>

<gadget id="calculator">1 + (7/11)</gadget>
<output>18/11 = around 1.636364</output>

<gadget id="calculator">(720/11) / (18/11)</gadget>
<output>40</output>

<result>40</result>