Two candles with different thickness and length, the long one can be lit for 4 hours, and the short one can be lit for 6 hours. If they are lit at the same time, after 2 hours, the remaining lengths of the two candles are just equal. What fraction of the length of the original short candle is the long candle?
两只粗细、长短都不同的蜡烛，长的一只可以点4小时，短的一只可以点6小时，将他们同时点燃，2小时后，两支蜡烛所余下的长度正好相等．原来短蜡烛的长度是长蜡烛的几分之几？
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/6) * 2</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) * 2</gadget>
<output>1/2 = around 0.5</output>

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

<gadget id="calculator">(2/3) / (1/2)</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">1 / (4/3)</gadget>
<output>3/4 = around 0.75</output>

<result>3/4 = around 0.75</result>