If a commodity is sold at the original price, the profit per piece is 25% of the cost, and later sold at 90% of the original price, the total profit obtained is 25% higher than the original. So how many times the sales volume after the price reduction is the original sales volume?
某种商品按原定价出售，每件利润为成本的25%，后来按原定价的90%出售，获得的总利润比原来增加25%．那么降价后的销售量是原销售量的多少倍？
<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">(5/4) - 1</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">(5/4) * (9/10)</gadget>
<output>9/8 = around 1.125</output>

<gadget id="calculator">(9/8) - 1</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">(5/4) / (1/8) / 1</gadget>
<output>10</output>

<gadget id="calculator">(1/4) * 10</gadget>
<output>5/2 = around 2.5</output>

<result>5/2 = around 2.5</result>