A ship travels from A to B at 25 kilometers per hour and arrives in 15 hours. The speed increased by 20% when returning, and how many hours did it take when returning.
一艘轮船从甲地开往乙地，每小时行25千米，15小时到达．返回时速度提高了20%，返回时用了多少小时．
<gadget id="calculator">25 * 15</gadget>
<output>375</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">25 * (6/5)</gadget>
<output>30</output>

<gadget id="calculator">375 / 30</gadget>
<output>25/2 = around 12.5</output>

<result>25/2 = around 12.5</result>