A car drives from point A to point B at a speed of 60 kilometers per hour and arrives at point B in 4 hours; if it is 80 kilometers per hour on the way back, how many hours will it take to reach point A?
一辆汽车以每小时60千米的速度从甲地开往乙地，4小时到达；若返回途中每小时80千米，几小时可到达甲地？
<gadget id="calculator">4 / 80</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">60 * (1/20)</gadget>
<output>3</output>

<result>3</result>