Two ships, A and B, are traveling towards each other from two docks at the same time. Ship A travels 40 kilometers per hour, and boat B travels 28 kilometers per hour. After traveling for 4 hours, the distance between the two ships is still 30 kilometers. What is the distance between the two docks of A and B? km?
甲乙两艘轮船分别从两个码头同时相向而行，甲船每小时行40千米，乙船每小时行28千米，两船行驶4小时后还相距30千米，甲乙两个码头相距多少千米？
<gadget id="calculator">40 + 28</gadget>
<output>68</output>

<gadget id="calculator">68 * 4</gadget>
<output>272</output>

<gadget id="calculator">272 + 30</gadget>
<output>302</output>

<result>302</result>