Xiao Ming walks to school when he goes to school, and takes a car to go home after school. It takes a total of 1.5 hours on the road. If you take a car back and forth, it only takes 0.5 hours on the road. If Xiao Ming walks back and forth, how many hours will it take in total?
小明上学时步行到学校，放学时乘车回家，路上一共需要1.5小时．若来回都乘车，则路上只需要0.5小时．假如小明来回都步行，则一共需要多少小时．
<gadget id="calculator">0.5 / 2</gadget>
<output>0.25</output>

<gadget id="calculator">1.5 - 0.25</gadget>
<output>1.25</output>

<gadget id="calculator">1.25 * 2</gadget>
<output>2.5</output>

<result>2.5</result>