canal is 500 meters long. The full length (3/20) was built on the first day, and the full length (1/10) was built on the second day. How many meters were built in two days?
一条水渠500米，第一天修了全长的(3/20)，第二天修了全长的(1/10)，两天共修多少米？
<gadget id="calculator">3 / 20</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(3/20) + (1/10)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">500 * (1/4)</gadget>
<output>125</output>

<result>125</result>