For a road, (1/5) of the entire road was repaired in 3 days, and there are 50 kilometers left, how much (1/2) is left after repairing in 10 days?
一条公路，3天修了整个公路的(1/5)，剩50千米，10天修了剩下的(1/2)还剩多少？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">50 * (1/2)</gadget>
<output>25</output>

<gadget id="calculator">50 - 25</gadget>
<output>25</output>

<result>25</result>