car travels from A to B at 40 kilometers per hour. After 5 hours of driving, a train travels from A to B at a speed of 90 kilometers per hour and stops at the midpoint of A and B. caught up with the car. How many kilometers are there between A and B?
一辆汽车从甲地开往乙地，每小时行40千米，开出5小时后，一列火车以每小时90千米的速度从甲地开往乙地，并在甲乙两地中点处追上了汽车．甲乙两地相距多少千米．
<gadget id="calculator">90 - 40</gadget>
<output>50</output>

<gadget id="calculator">5 / 50</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">40 * (1/10)</gadget>
<output>4</output>

<gadget id="calculator">90 * 4 * 2</gadget>
<output>720</output>

<result>720</result>