Master Wang planned to finish processing a batch of parts in 15 days. Due to improved technology, work efficiency increased by 25%. How many days did Master Wang actually process?
王师傅加工一批零件计划15天完成，由于改进技术，工效提高了25%，王师傅实际加工了多少天？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 + (1/4)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(5/4) * (1/15)</gadget>
<output>1/12 = around 0.083333</output>

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

<result>12</result>