A passenger car and a truck depart from cities A and B at the same time and meet each other in 4 hours. It is known that passenger cars travel an average of 89 kilometers per hour, and trucks travel an average of 71 kilometers per hour. How many kilometers are there between A and B?
一辆客车和一辆货车分别从甲乙两城同时相对开出，4小时相遇．已知客车平均每小时行驶89千米，货车平均每小时行驶71千米，甲乙两城相距多少千米？
<gadget id="calculator">89 + 71</gadget>
<output>160</output>

<gadget id="calculator">160 * 4</gadget>
<output>640</output>

<result>640</result>