A car and a truck leave from city A and city B respectively at the same time. After 4.6 hours, the distance between the two cars is 48 kilometers. The car travels 81.2 kilometers per hour, and the truck travels 68.8 kilometers per hour. How many kilometers are there between A and B?
一辆小汽车和一辆货车分别从A城和B城同时相对开出，4.6小时后两车还相距48千米，小汽车每小时行驶81.2千米，货车每小时行驶68.8千米．A、B两城相距多少千米？
<gadget id="calculator">81.2 + 68.8</gadget>
<output>150</output>

<gadget id="calculator">4.6 * 150</gadget>
<output>690</output>

<gadget id="calculator">690 + 48</gadget>
<output>738</output>

<result>738</result>