The perimeter of a rectangle is 1 meter, if the length increases by (1/3) and the width increases (1/4), then the perimeter increases by 30 cm. Find the original area of this rectangle.
一个长方形的周长是1米，如果长增加(1/3)，宽增加(1/4)，那么周长增加30厘米．求这个长方形原来的面积．
<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<gadget id="calculator">100 / 2</gadget>
<output>50</output>

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

<gadget id="calculator">1 * 50 * (1/4)</gadget>
<output>25/2 = around 12.5</output>

<gadget id="calculator">15 - (25/2)</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/3) - (1/4)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">(5/2) / (1/12)</gadget>
<output>30</output>

<gadget id="calculator">1 * 50</gadget>
<output>50</output>

<gadget id="calculator">50 - 30</gadget>
<output>20</output>

<gadget id="calculator">30 * 20</gadget>
<output>600</output>

<result>600</result>