Car A and car B drive oppositely from two places ab at the same time, and meet at a distance of 40 kilometers from the midpoint after several hours. It is known that it takes 8 hours for car A to complete the journey, and 10 hours for car B to complete the journey. How many kilometers are the distance between ab and ab?
甲乙辆车同时从ab两地相对开出，若干小时后在距中点40千米处相遇．已知，甲车行完全程要8小时，乙车行完全程要10小时，ab两地相距多少千米．
<gadget id="calculator">10 - 8</gadget>
<output>2</output>

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

<gadget id="calculator">10 + 8</gadget>
<output>18</output>

<gadget id="calculator">40 * 1 * 18</gadget>
<output>720</output>

<result>720</result>