Two passenger and freight cars depart from A and B respectively at the same time. After 3 hours, the passenger car arrives at the midpoint, and the truck is still 90 kilometers away from the midpoint. It is known that the speed ratio of trucks to passenger cars is 2:3. How many miles is the distance between A and B?
客货两车分别从A、B两地同时相对开出，3小时后客车到达中点，货车离中点还有90千米．已知货车与客车速度的比是2：3．AB两地相距多少千米？
<gadget id="calculator">3 - 2</gadget>
<output>1</output>

<gadget id="calculator">90 / 1</gadget>
<output>90</output>

<gadget id="calculator">3 + 2</gadget>
<output>5</output>

<gadget id="calculator">90 * 5</gadget>
<output>450</output>

<gadget id="calculator">450 + 90</gadget>
<output>540</output>

<result>540</result>