It takes 8 hours for the express train to go from A to B, and 10 hours for the slow train to go from B to A. Both cars leave A at the same time. Two places B drive opposite each other. When they meet, the express train is still 100 kilometers away from B. Find the distance between A and B?
快车从甲地开往乙地要用8小时，慢车从乙地开往甲地要用10小时，两车同时从甲．乙两地相对开出，相遇时，快车离乙地还有100千米，求甲乙两地之间的路程？
<gadget id="calculator">4 + 5</gadget>
<output>9</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">100 / (4/9)</gadget>
<output>225</output>

<result>225</result>