The distance between A and B is 90 kilometers. Cars A and B start from places A and B at the same time and drive toward each other. When they meet, car A travels 30 kilometers longer than car B. Excuse me: When car A arrives at B How many kilometers is the distance between car B and A?
A、B两地相距90千米，甲，乙两车分别从A，B两地同时出发，相向而行，相遇时甲车比乙车多行驶了30千米，请问：当甲车到达B地时，乙车距离A地多少千米？
<gadget id="calculator">90 + 30</gadget>
<output>120</output>

<gadget id="calculator">120 / 2</gadget>
<output>60</output>

<gadget id="calculator">90 - 60</gadget>
<output>30</output>

<gadget id="calculator">120 / 2 / 30</gadget>
<output>2</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">90 * (1/2)</gadget>
<output>45</output>

<gadget id="calculator">90 - 45</gadget>
<output>45</output>

<result>45</result>