A ship sails from port A to port B for 16 hours at a speed of 25 kilometers per hour. Sailing against the current when returning, traveling 20 kilometers per hour, how many hours will it take to return?
轮船从甲港顺水航行开到乙港，以每小时行25千米的速度行了16小时．回来时逆水航行，每小时行20千米，回来要用多少小时？
<gadget id="calculator">16 / 20</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">25 * (4/5)</gadget>
<output>20</output>

<result>20</result>