After the speed of the train is increased, the time it takes to pass through a certain cave is reduced from 40 seconds to 30 seconds now. What percentage of the time it takes to pass through the cave now?
列车提速后，穿过某个山洞所用时间由原来的40秒减少到现在的30秒，现在穿过山洞的时间是原来的百分之几？
<gadget id="calculator">30 / 40</gadget>
<output>3/4 = around 0.75</output>

<result>3/4 = around 0.75</result>