In order to alleviate traffic congestion, a city is widening roads. The road width of Hongxing Road has been widened by 15m from the original 12m. By what percentage?
为了缓解交通拥挤的状况，某市正在进行道路拓宽．红星路的路宽由原来的12m拓宽了15m，拓宽了百分之几？
<gadget id="calculator">15 - 12</gadget>
<output>3</output>

<gadget id="calculator">3 / 12</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>