Cars A and B start from the east and west cities at the same time and drive towards each other, and meet each other in 4 hours. It is known that car A travels an average of 85 kilometers per hour, and car B travels an average of 65 kilometers per hour. How many kilometers are there between the east and west cities?
甲、乙两车同时从东、西两城出发相向而行，4小时相遇，已知甲车平均每小时行85千米，乙车平均每小时行65千米．东、西两城相距多少千米？
<gadget id="calculator">85 + 65</gadget>
<output>150</output>

<gadget id="calculator">150 * 4</gadget>
<output>600</output>

<result>600</result>