Wang Gang walks 3.5 kilometers per hour from home to school, and arrives in 1.6 hours. When returning from school, he walks 4 kilometers per hour. How many hours does it take Wang Gang to get home?
王刚从家到学校每小时步行3.5千米，1.6小时到达，从学校返回时，每小时行4千米，王刚返回家要多少小时才能到达？
<gadget id="calculator">1.6 / 4</gadget>
<output>0.4</output>

<gadget id="calculator">3.5 * 0.4</gadget>
<output>1.4</output>

<result>1.4</result>