small boat takes 2 hours to go back and forth from point A to point B. When it comes back, it travels 7.5 kilometers per hour more than the speed at the time of going. Therefore, the second hour travels 5 kilometers longer than the first hour. Ask A The distance between the ground and the ground.
一只小船从甲地到乙地往返一次共用了2小时，回来时是顺水，比去时的速度每小时多行驶7.5千米，因此第二小时比第一小时多行5千米，求甲地与乙地之间的距离．
<gadget id="calculator">7.5 - 5</gadget>
<output>2.5</output>

<gadget id="calculator">2.5 / 7.5</gadget>
<output>0.333333</output>

<gadget id="calculator">2.5 / 0.333333</gadget>
<output>7.500008</output>

<gadget id="calculator">1 + 0.333333</gadget>
<output>1.333333</output>

<gadget id="calculator">7.500008 * 1.333333</gadget>
<output>10.000008</output>

<result>10.000008</result>