The difference between A and B piles of coal is 60 tons. After 15% of the coal is used up, how many tons is the difference?
甲、乙两堆煤相差60吨，都用去15%后，还相差多少吨．
<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">1 - (3/20)</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">100 * (17/20)</gadget>
<output>85</output>

<gadget id="calculator">100 - 60</gadget>
<output>40</output>

<gadget id="calculator">40 * (17/20)</gadget>
<output>34</output>

<gadget id="calculator">85 - 34</gadget>
<output>51</output>

<result>51</result>