A road construction team paved a section of railway. The original plan was to pave 3.2 kilometers per day, but the actual pavement was 25% more than the original plan every day. It took 12 days to finish paving this section of railway. (Solve with ratio)
一个筑路队铺一段铁路，原计划每天铺3.2千米，实际每天比原计划多铺25%，实际铺完这段铁路用了12天，原计划用多少天铺完？(用比例解)
<gadget id="calculator">3.2 * 12</gadget>
<output>38.4</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">3.2 * 12 * (1/4)</gadget>
<output>9.6</output>

<gadget id="calculator">38.4 + 9.6</gadget>
<output>48</output>

<gadget id="calculator">48 / 3.2</gadget>
<output>15</output>

<result>15</result>