A ship sails between two ports on a river with a water speed of 60 per hour. It takes 4 hours to go down the water and 7 hours to go back up. Ask: The distance between these two ports?
一艘轮船在一条河的两个港口间航行，水速为每小时6十来，顺水下行需要4小时，返回上行需要7小时．求：这两个港口之间的距离？
<gadget id="calculator">6 * 4</gadget>
<output>24</output>

<gadget id="calculator">6 * 7</gadget>
<output>42</output>

<gadget id="calculator">24 + 42</gadget>
<output>66</output>

<gadget id="calculator">7 - 4</gadget>
<output>3</output>

<gadget id="calculator">66 / 3</gadget>
<output>22</output>

<gadget id="calculator">22 + 6</gadget>
<output>28</output>

<gadget id="calculator">28 * 4</gadget>
<output>112</output>

<result>112</result>