Cars A and B start from places A and B respectively, and drive back and forth between A and B. It is known that the speed of car A is 15 kilometers per hour, and the speed of car B is 35 kilometers per hour. The place where the two vehicles met for the third time (here specifically refers to the face-to-face meeting) is exactly 100 kilometers away from the place where the two cars met for the fourth time. Then, how many kilometers is the distance between A and B?
甲、乙两车分别从A、B两地出发，在A、B之间不断往返行驶，已知甲车的速度是每小时15千米，乙车的速度是每小时35千米，并且甲、乙两车第三次相遇(这里特指面对面的相遇)的地点与第四次相遇的地点恰好相距100千米，那么，A、B两地之间的距离等于多少千米．
<gadget id="calculator">3 * 5</gadget>
<output>15</output>

<gadget id="calculator">3 + 7</gadget>
<output>10</output>

<gadget id="calculator">15 - 10</gadget>
<output>5</output>

<gadget id="calculator">3 * 7</gadget>
<output>21</output>

<gadget id="calculator">10 * 2</gadget>
<output>20</output>

<gadget id="calculator">21 - 20</gadget>
<output>1</output>

<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">100 / 4</gadget>
<output>25</output>

<gadget id="calculator">25 * 10</gadget>
<output>250</output>

<result>250</result>